Help with Board Question ( No Word Count), and Case Study. APA Format Throughout to Include Reference Page. 

Board Question

To most people, a polymer is synonymous with plastic. Technically, there are many different types and uses of plastic. For this discussion board, let us narrow it down to plastic food containers. The most popular or controversial issue that has come up to date is regarding BPA (bisphenol A). BPA is a monomer in some plastics, including polycarbonate. For consumer safety, products must undergo a variety of tests before the U.S. Food and Drug Administration (FDA) will allow the polymer to be used in products that can come in contact with food and drink. What are your thoughts about this issue? Do you feel that BPA should continue to be used in plastic food containers? Why, or why not?

Unit VII Case Study

For this assignment, you are the lead incident commander for a hazardous materials incident similar to those that have been introduced in this course. In this scenario, HLF Polyurethane Manufacturing was undergoing a maintenance activity in which an acid gas feed line segment required replacement. Pressure gauges were not installed in the line to monitor activity or to indicate if the line was operational. Upon initiating the line breaking activity (opening the line to the atmosphere) under self-contained breathing apparatus (SCBA), there was an uncontrolled release of acid gas. A nearby welding operation provided the ignition source and the flammable gas was ignited.

The following actions were initially taken:

The evacuation alarm was sounded and the facility emergency response team (ERT) was activated.
The plant manager and the local fire department were notified of the incident.
The incident command was established at the facility office near the main access gate to the south (this is the furthest distance within the property boundary from the incident location).
The incident commander implemented actions required under the approved emergency response plan.
The ERT was not able to immediately isolate the source of the incident.
The fire department arrived on location and assumed the incident command of the event.

Additional Relevant Information:

The facility encompasses an area measuring 2000 feet by 1400 feet.
The nearest residential community is located approximately 1000 feet to the northeast.
A plastic recycling plant is located along the south fence boundary of the refinery.
A major interstate highway runs directly parallel to the plant.
The ambient temperature on the day of the incident was 85° F and the wind was blowing at 7 mph from the southwest to the northeast.
Work crews were scheduled to work 12-hour shifts, 24-hours a day, to complete the incident response.
The facility has a trained ERT that can respond to incidents.

Your essay must address the following:

Summarize the incident.
Identify all hazardous materials involved, their classifications and their physical properties.
Discuss chemical incompatibility and interactions relevant to this incident.
Discuss any short or long term mitigation necessary.
Explain how the lead incident commander should respond to this incident based on the Emergency Response Guidebook (ERG). Click the link below to access the ERG at the Pipeline and Hazardous Materials Safety Administration website:

Pipeline and Hazardous Materials Safety Administration. (n.d.). Emergency Response Guidebook (ERG). Retrieved from

http://www.phmsa.dot.gov/hazmat/library/erg

Explain the corrective action plan that should be implemented based on the ERG to prevent a reoccurrence of this event.

Your response must be at least one page in length (not counting the cover page or reference page). All sources used, including the text, must be referenced. Paraphrased and quoted materials must have accompanying in-text and reference citations in APA format.

Your response must be at least one page in length (not counting the cover page or reference page). All sources used, including the text, must be referenced. Paraphrased and quoted materials must have accompanying in-text and reference citations in APA format.

1

Course Learning Outcomes for Unit VII

Upon completion of this unit, students should be able to:

1. Examine chemistry fundamentals.
1.1 Identify the classifications and physical properties of hazardous materials involved in a gas

release incident.

4. Evaluate chemical interactions as they relate to control of potential hazards.
4.1 Identify the toxic gases produced when polymers thermally decompose or burn.
4.2 Determine the chemical reactions, interactions, and incompatibility of common polymers as

related to potential emergency response situations.

8. Apply information resources commonly used in emergency response operations.
8.1 Explain the actions an incident commander would take when responding to a gas release

incident based on information in the Emergency Response Guidebook (ERG).
8.2 Explain the corrective action plan that should be implemented to prevent reoccurrence of a gas

release incident based on information in the ERG.

Course/Unit
Learning Outcomes

Learning Activity

1.1
Unit VII Lesson
Chapter 14 Reading
Unit VII Case Study

4.1
Unit VII Lesson
Chapter 14 Reading
Unit VII Case Study

4.2
Unit VII Lesson
Chapter 14 Reading
Unit VII Case Study

8.1
Unit VII Lesson
Chapter 14 Reading
Unit VII Case Study

8.2
Unit VII Lesson
Chapter 14 Reading
Unit VII Case Study

Reading Assignment

Chapter 14:
Chemistry of Some Polymeric Materials, pp. 606-642

UNIT VII STUDY GUIDE

Chemistry of Polymers

2

UNIT x STUDY GUIDE

Title

Unit Lesson

In this unit, we will focus our study on the more complex hydrocarbons known as polymers discussed in
Chapter 14.

Polymers

Meyer (2014) suggests that a contemporary culture could not long endure without the goods or products that
the polymer industry provides. These polymeric products include clothing, household/office, indoor and
outdoor gadgets, and furnishings that are manufactured from natural and synthetic polymers.

Polymers are not ordinarily considered hazardous materials since they are stable at ambient conditions;
however, most of the products burn and produce toxic gases (Meyer, 2014). Because of their widespread
use, it is of benefit to understand why and how they can pose hazards, especially during fires. For this unit,
we will study the features and structural characteristics of commonly encountered polymers as well as the
hazards that they pose when they burn.

What are polymers? The International Union of Pure and Applied Chemistry (IUPAC) (2017) defines polymers
as substances or macromolecules that made up of large molecules that weigh from a few thousand to millions
or grams per mole. The structure of a macromolecule is essentially comprised of multiple repetitions of units
derived, actually or conceptually, from molecules of low molecular mass.

Polymers can be natural or synthetic, but most of us probably associate polymers with the synthetic ones
such as plastic. Examples of natural polymers include protein, starch, cellulose, and DNA that make up most
of the structures of living tissue. Synthetic polymers include polyvinyl chloride (PVC), polycarbonate, and
polyethylene.

Types of synthetic polymers: Synthetic polymers are often referred to as plastics, and most of them can be
classified into the categories of elastomers, thermoplastics, and thermosets:

 Thermoplastics are polymers that soften when heated but return to their original condition on cooling
to ambient temperature (e.g., polyvinyl chloride (PVC), polyethylene).

 Thermosets are polymers that cannot be remolded once they have solidified, such as polyurethane.

 Elastomers have elasticity like rubber (Polymer Science Learning Center, 2005).

Polymerization is the chemical reaction during which monomers are linked and cross-linked to form
polymers. The polymerization reaction is characterized by the macromolecule/polymer that is
produced (see Figures 14.1 and 14.2 on pages 608 and 609 of the textbook). According to Meyer
(2014), chemists have found when they examined the three-dimensional structure of polymers that
the chains of repeating units are invariably cross-linked as shown in Figure 14.3 on page 609 of the
textbook.

Note the following information about polymers:

 Intentional cross-linking technique for polymers is used during the production of thermoset plastics to
make the polymer denser, stronger, and even elastic.

 Macromolecular chains within polymers can also be folded, coiled, stacked, looped, or intertwined
into definite three-dimensional shapes.

 Polymer manufacturers sometimes discover that their products are too stiff and brittle for their
intended use. These undesirable features can often be overcome by adding a plasticizer to the
polymer. This is usually a liquid that manufacturers use to dissolve the polymer.

 These processes are accomplished primarily by unique chemical reactions called addition and
condensation.

For information about addition polymerization, see the example illustration on page 610 in the
textbook, which shows how the polymers can be formed by the addition of the same units (starting
with the styrene monomer). For more examples of polymers formed by addition polymerization, see
Table 14.1 on page 612 in the textbook.

3

UNIT x STUDY GUIDE
Title

A common example of the condensation polymerization process is the reaction between alcohol and
organic acids. In the textbook, the example illustrates that the monomer ethylene glycol can be
reacted with succinic acid (an organic acid) to form an intermediate product. This intermediate
product has reactive groups that will form more intermediate products that will get more complex as
the reactions continue until the end product is formed. In this example, the polymer produced is
polyester. See Table 14.2 on page 615 in your textbook for more examples of this type of
polymerization reaction.

It is also important to note polymer decomposition and combustion. Most products produced from
natural and synthetic polymers are combustible when exposed to an ignition source. According to
Meyer (2014), most products often melt and thermally decompose into the monomers from which
they were made. This melting is associated with both beneficial and detrimental effects.

Other general features associated with their combustion are discussed on pages 617-618 (e.g., flashover) in
your textbook. Flashover is the spread of fire from the burning area to other areas physically isolated from the
initial source of the fire. Firefighters need to be concerned with this phenomenon. They should also be
concerned with the smoke generated and the voluminous amount of toxic gases produced not just from the
polymers, but from non-polymeric products that may also burn during a fire.

Vegetable and animal fibers: Many common textiles are produced from naturally occurring
vegetable and animal fibers. Cotton and linen are examples of vegetable fibers; whereas, wool and

silk are examples of animal fibers. These naturally occurring fibers may be used to produce textiles,
or they can be chemically altered to produce synthetic fibers from which the textiles are produced.
Vegetable and animal fibers are often mixed with combustible oil such that the DOT regulates their
transportation as hazardous materials.

Synthetic polymers that are commonly encountered are discussed in detail in the textbook. They
include the following:

 Polyvinyl polymers: These are produced from multiple vinyl compounds. Other examples of this
polymer are polyethylene, polypropylene, and polyvinyl chloride.

 Epoxy resins

 Formaldehyde-derived polymers

 Polyurethane: All polyurethane burns when exposed to sufficient heat (Meyer, 2014).

 Heat and fire resistant polymers

 Rubber and rubber products

 Natural rubber

 Synthetic rubbers

Responding to incidents involving the burning of rubber: To understand the substances produced when
rubber products burn, we need to recall the general features and constituents of their chemical formulations.
According to Meyer (2014),

 As they burn, rubber products vulcanized with sulfur or sulfur-bearing compounds produce carbon
monoxide, sulfur dioxide, and water vapor.

 The smoke associated with rubber fires is extraordinarily dense and black.

 To prevent or reduce respiratory concerns or fatalities among firefighters, the use of self-contained
breathing apparatus is always warranted (pp. 641-642).

The polymer industry has dramatically altered our way of life, so environmental health and safety (EHS) and
fire science (FS) professionals, especially responders, will encounter them virtually everywhere. Because they
are stable in ambient conditions, they are not ordinarily considered hazardous materials. However, most
polymeric products burn and generate toxic gases on combustion. For these reasons, the burning of polymers
is a topic of great concern, especially to firefighters.

4

UNIT x STUDY GUIDE
Title

References

International Union of Pure and Applied Chemistry. (2013). What are polymers? Retrieved from

What are polymers?

Meyer, E. (2014). Chemistry of hazardous materials (6th ed.). Upper Saddle River, NJ: Pearson.

Polymer Science Learning Center. (2005). Elastomers. Retrieved from http://pslc.ws/macrog/elas.htm

Suggested Reading

This is an easy to understand webpage that defines elastomers or polymers. If you are having trouble with
these concepts, this is a good learning tool.

Polymer Science Learning Center. (2005). Elastomers. Retrieved from http://pslc.ws/macrog/elas.htm

http://pslc.ws/macrog/elas.htm

3/25/20, 10:17 PMElastomers

Page 1 of 4https://pslc.ws/macrog/elas.htm

All About
Elastomers

Keywords
crosslinking, entropy

Elastomer is a big fancy word, and all it means is “rubber”. Some
polymers which are elastomers include polyisoprene or natural
rubber, polybutadiene, polyisobutylene, and polyurethanes. What
makes elastomers special is the fact that they bounce. But just saying
“they bounce” is kind of vague. Let’s be more specific. What makes
elastomers special is that they can be stretched to many times their
original length, and can bounce back into their original shape without
permanent deformation.

But why?

Putting Entropy to Work for You!

Entropy is disorder. Things in our universe like
entropy, and tend to become more disordered.
That’s why keeping your room messy is easier
than keeping it neat. This dog is named Entropy,
which is appropriate because she runs around
like free-range chicken with its head cut off whenever her human lets

https://pslc.ws/macrog/glossary.htm%23xlink

https://pslc.ws/macrog/glossary.htm%23entropy

https://pslc.ws/macrog/isoprene.htm

https://pslc.ws/macrog/pb.htm

https://pslc.ws/macrog/pib.htm

https://pslc.ws/macrog/urethane.htm

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Page 2 of 4https://pslc.ws/macrog/elas.htm

her in the house. Polymer molecules are the same way. The
molecules in a piece of rubber, any kind of rubber, have no order to
them. They just wind and tangle around each other in one jumbled
mess. They’re perfectly happy this way.

But now pull on the piece of rubber, and everything gets upset. The
molecules are forced to line up in the direction in which the rubber is
being pulled. When the molecules line up like this they become more
ordered. If you stretch it far enough the chains will line up straight
enough to crystallize. They don’t like this. Remember, they like
entropy (being disordered).

Now when you let go of this rubber sample you’ve been stretching,
the molecules will quickly go back to their tangled and disordered
state. They do this to return to a state of entropy. Remember, they like

https://pslc.ws/macrog/crystal.htm

3/25/20, 10:17 PMElastomers

Page 3 of 4https://pslc.ws/macrog/elas.htm

entropy. When this happens, the sample pops back to its original
shape.

Glass or rubber?

Of course, not all amorphous polymers are elastomers. Some are
thermoplastics. Why is this? Whether an amorphous polymer is a
thermoplastic or an elastomer depends on its glass transition
temperature, or Tg. This is the temperature above which a polymer
becomes soft and pliable, and below which it becomes hard and
glassy. If an amorphous polymer has a Tg below room temperature,
that polymer will be an elastomer, because it is soft and rubbery at
room temperature. If an amorphous polymer has a Tg above room
temperature, it will be a thermoplastic, because it is hard and glassy
at room temperature. So a general rule of thumb is that for
amorphous polymers, elastomers have low Tg’s and thermoplastics
have high Tg’s. (But be careful, this only works for amorphous
polymers, and not for crystalline polymers.)

One Molecule Can Do a Lot

To help elastomers bounce back even better it helps to crosslink
them. Crosslinking is the forming of covalent links between the
different polymer chains, joining them all into a single networked
molecule. That’s right, most objects made of rubber contain only one
molecule! When the polymer chains are joined together like this, it is
even harder to pull them out of their original positions, and so it
bounces back even better when stretched.

But this makes elastomers hard to recycle. Think about it. How does
one melt down one molecule? To make recyclable elastomers we
need to find a way to tie the molecules together when the rubber is
being used, but one which would allow the chains to separate when
being processed. The answer is called a thermoplastic elastomer.

https://pslc.ws/macrog/plastic.htm

https://pslc.ws/macrog/tg.htm

https://pslc.ws/macrog/crystal.htm

https://pslc.ws/macrog/xlink.htm

https://pslc.ws/macrog/tpe.htm

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Would you like to read an interesting story about the first uses of
rubber by the Mayans? They invented a game similar to basketball,
but without somewhat different rules and outcomes…

Return to Level Three Directory

Return to Macrogalleria Directory

| Copyright © 2003 – 2020 Polymer Science Learning
Center |

https://pslc.ws/macrog/elastory.htm

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http://pslc.ws/

CHAPTER 14

Counely of Pyrocool Techn ologi es. Inc.,
Monroe, Vir gm1a.

i:fh,fo4M
addition polymer, p . 609
amide, p . 62

0

aminoacid, p . 619
atactic polymer, p . 628
autopolymerization, p. 6 16
cellulose, p. 623
condensation polym e r, p. 609
copolymer, p. 609
cotton, p. 62 1
cross -l inking, p. 609
depolymerization, p. 61 7
distillate-aromatic-extract oil, p. 641
ebonite, p. 640
elastomer, p. 608
epoxy resin, p . 632
fiber, p. 608

Chemistry of Some
Polymeric Materials

Flammable Fabrics Act. p. 621
flashover, p . 618
foam rubber, p . 641
inhibitor, p . 616
isocyanate, p. 633
isotactic polymer, p. 628
linen, p. 62 1
macromolecule, p . 607
monomer, p . 608
na t ural rubber, p . 637
neoprene, p. 639
nitrile, p. 620
nitre compound, p. 620
plastics, p. 607
polyamide, p. 633
polyester, p. 613

polymerization, p. 608
polymer, p . 607
polyurethane, p . 633
rubberized asphalt, p. 641
silk, p. 625
styrene–butadlene rubber, p. 639
syndiotactlc polymer, p. 628
synthetic rubber, p. 638
textile, p. 608
thermoplastic pol ymer, p. 607
thermosetting polymer, p. 607
urethane {carbamate), p. 633
vinyl polymer, p. 626
vulcanization, p. 638
vulcanized rubber, p . 638
wool, p . 625

Associate the physical and hea lth haza rds of the monomers not ed in thi s chapte

r

with rhe information provided by their haza rd diamonds a nd GHS pictograms .
Describe the ge neral nature of the polymerization reaction.
Distinguish berween add itio n and condensation polyme ri za tio n reactions.
Describe how cross-linking and the use of pla sticize rs alters th e physica l features
of polymers.

606

Discuss the ge n~ra l phenomena that occu r whe n polymers bum o n expos ure to hea t.
Identify the tox ic gases prod uced whe n polymers thermally decompose o r burn.
Desc ribe a nd compare the macromolecular structur es of the com mon vege cable and
aninia l fibers.

1 Ident ify the com mo n ~r~duc ts made from polyet hylene, polypropylene, poly(vi nyl
chloride), polyacry lon itnl e, poly (merhyl mer hacry late ), polyacryla mide, phenol-
for n1 aldc hy_de, u~ea-fo rmal.dehyde, melamine-fo rmaldehyde polymers, and polyure-
th.’.llle, a nd 1dent1fy the toxic ~ases produced when they burn o r smolder.

1
Dcsc~ibe how natural m?ber 1s vulcani zed.

1 Jdenufy the label s: ma~ km gs, and placa rds that DOT requires on packaging of th e
01011 omcrs noted m this chap ter and the transport ve hicl es used for their shipment.

0 ver the_ past .7s yea rs, the polymer industry has dramatica ll y a ltered our way o f life. It 1s unlikely that a modern civili zed socie ty could long survive without the wa res it provides . In ~oday’s wo rl d, we regularly use products manufactured
front both natural and synthetic polymers. Our clothing is made from po lymeric fibers,
includ ing cotton, pol yeste rs, nylon , and polyacry lics. O ur homes are constructed fr o m
wood, in sul ated with p~lystyrene, carpeted wit h polypropylene, coated wi th polyacrylic
plints, and de~o rated w1_th polyacrylo nitril e and other po lymeric fabrics.

An appreciable portion of o ur automobiles also ha ve been manufactured from poly·
me rs. Often, the bumpers are made o f an acrylonitrile-butadiene-sty rene copolymer, the
roofs a re m.’.lde of poly(viny l chloride ), the upholstery is cush ioned with polyurethane,
311d the rubber tires are manufactured from a sty rene-butadiene co polymer.

Because they arc sta ble at ambi ent conditions and do not routinely pose a health risk ,
polymers are not ordinarily considered ha za rd ous materi als. However, most polyme ric
prod ucts burn and generate to xic gases on combustion. No t o nl y do most po lymeric prod-
ucts burn, but their combustion is involved in vi rtuall y all common fires. For these reasons,
the burning of polymers is a topic of great concern to firefighters.

ln thjs chapter, to understand why they pose special haza rd s during fires, we examine
the fea tures and structural characteristics of several commo nl y encountered polyme rs.

14.1 WHAT ARE POLYMERS?
Polymers are substances that are best characteri zed b)’ the relativel y sizable nature of
their mo lecules. Because these molec ules are substa ntiall y larger tha n those o therwise
encountered, chemist s ca ll them macromolecules. Each polymer macromolecule com-
prises a number of repeati ng small er uni ts ; a polymer is a compound typica ll y composed
of hundreds o r tho u sands of repeati ng units.

Polymers sometimes are desc ribed by their res ponse to heat. Some soften when exposed
to heat and ma y be physically manipulated to produce new shapes. Upon cooling, they retain
th ese shapes until they are heated again. These polymers are called thermoplastic polymers.
The following a re examples o f thermoplastic polymers: polyethy lene, polypro pylene, poly-
sty rene, poly(ct hylene terephthala te ), and poly(vinyl chloride).

pol ym e r A high •
molecular-we ight
substance produced by
the linkage and cross-
linkage of its multiple
subunits (monomers)

ma cro mol e cule The
g iant molecule of
which polymers are
composed, comprising
an aggregation of hun·
dreds or thousands of
atoms and typically
consisting of repeating
chem ical units linked
together into chains
and cross-linked into
complex three-dimen –
sional networks
t h ermo p lasti c polym e r

Any polymer that
softens when heated
but returns to its
orig inal condition on
cooling to ambient
temperature

Other polymers soli dify or set irreversibly when they a re h ea ted. They are ca lled
thermosetting polymers. Polyurethane is an exa mple of a thermosetting pol ym er.

Polymers are a lso classified according to the ways their manufactured products a re
USl’ d. For insta nce, some polymers a re used to produce plastics-items that can be shaped
by 1neans of molding, casting, extrusion, calendering, laminating, foaming, a nd b lowing.
Exa mples of so me com mon plastics a re poly (vin yl chloride ), polystyrene, and poly(methyl
niet_ha cryla te ). T he polymers in plastic products usuall r are combined wi th other materi-
als including fillers, reinforcing agents, and fi re reta rd ants .

th erm o setting po ly me r
• Any polymer that
cannot be remolded
once it has solidified

plast ics • Any of a
variety of synthet ic
polymeric substances
that ca n be molded
and shaped

Chapter 14 Chemistry of Some Polymeric Materials 607

I

lJ

f1 btr • Apo lymer ,c
subs tance t ha t can be
sep a rated in to thr eads
or thread -h ke
stn.ictures

text,1• Afab r,c
produ ced by weav ing
fi ber!

elastome r A syn thetic
po tym erthate longates
o r ruetches under
stra m but 1s 1n capab le
ofreta in ingthedefo r-
mat 1onwhenthestra in
,sre leased

po lymen zat1o n The
chem ica l react iondur-
mg wh ichmonomer
molKulesarel inked
and cros.s- finked into
macromolecules

mono me r • One or
more of the single sub-
stancesthatcombmeto
produce a polymer

n1 he11 c po l)n u.•rs are 1bed :i s thre:td:; ur yarn s colleqJ\d
Som~ n,11ur,1l ind S) h.1r 1Ctcn zed b) :l high tl’n IC’lt} and :l h,gh ratio of \en ‘th > tall rd

fibers l lH·se pol) rnt’ rsarec ) 11 d1fferw1del} mfor111 , fll’x1b1ht}, g tod1arn.
ete r ((~t~~;~i ~l ~:;,~dfit~ -~:1~ cu;e~:uurnll), others are produced synthet1

1 t gf I mcrs demed from \cgerable and a111111.1l so ur ces The)
::r:; 1

0
t~ I~ S) nthrnc fi bers.ire a clJss of pol r mers made ln some

T\\ O ~xa~l rs of S} nthw c f,lxr s arc 11) lon and pol }'(,1cry lomtrd e ) Sy nrhet1c f1
in cl ude I~ mers rh;it h.i\e been chermcall} modified in some\\ ,t y The}
fi ciurc ~mcroul good:; mcludmg rope. \\O\en clot h, maned fabrics, b
o1ha bwldmg and msulJung maten:ils, as \\ell as the stuffms m pi ll ows

Natural and S}nthetK fibe rs are\\ oven or knitted to produ ce tex tiles These are llr
such J S gJrment !i, car pets, carprt padding, to\\els, currn111s, bla nket s, mattre sses,~:
uphol ster >· fabrics. . f ·

A po lymer may also br 311 elastom e r. Thts 1s a type o sr mheuc polymer that 15 char.
actcrized by the ability of its molecules to elo ngat e when st rained and to reversibly assulllc
their onginal shape when the tension ha s been released. Exa~1ples of elas tomers are n~
prcn e and n.s – !,4 -polybutad,ene. Products made from them include rubber bands,bt\t~
foom,ear, \’ehicular ures, and the inner tub es of m es.

Various mean s ha ve been used to name pol ymers. Although seve ral common na~
are used, chen usts often place the prefix poly• bef?re th e na_me of the substances US(d

10
produce specific pol yme rs. Polyeth yle ne, po l}•( v1~ yl chlori_de ), and polyst yrene are

10
named because they are produced from ethylene, vmyl ch londe, and styrene, resprcti\·d
When l po lymer is manufactured from a number of sub stances , a ll thei r names may~
included 111 th e nam e of th e po lymer. The acrylonitrile-?u.radiene-sryrene copolymer com.
monl y used in plastic sewe r pipes is so named beca u se it 1s ma~e from ac~ lon itnle, buu.
diene, and styre ne. In ch is msiance. the nam e ha s been a~ br_ev1ated for _ simplicity to ABS
copolymer, where each letter represent s a monomer used m its prod uet1011.

14.2 POLYMERIZATION
Pol yme ri zation is a unique ry pe of chemical reaction in vo lving the union of cmam i Ub.
stances ca lled monomers. T he equauons for such reactions genera ll y ar e denoted as fol.
lows, where ,\ an d 13 a re arbitrary monom ers and a and b arc relati vely large numbm :

aA – bB – Po lyml’r

Onl y a select number of compounds undergo polymerization.
A pol yme riza tion rea ction is character ized by the nature of the macromo! eculr1 l!

produces. These macromolecules can be de sc ribed as foll o ws:

Figure 14 . l illustrates one type of po lyme ri c ma cromolecule. It s structure reS(:mbki
the midsection of a fr ei ght trai n ha vi ng identical box ca rs. Like a boxca r, the repeatmg
un it in this portion of th e macromolecul e ha s couplings at its front and rear ends.
here sy mbo li zed by chemica l bond s.
Figure 14 .2 illustra tes a seco nd type of polymeric macrom o lec ul e. It s s1ruc1u1c
resemb les the mid section o f a freight tra in th a t has a lternating di ss1milar ra1k,m.

FI GU RE 14 . 1 Th ,s mdsea,on of a fre 1gh 1 tra n c011s1sts of identical ,nterconnected ra,lcars It re semble, the partial ,truct ure of po’fE~l
v. ho, e macromo ‘ecu ‘eshavetnerepeatingun ,t , ,.,,CH.,-( , .,,.,.,.

608 Chapt er 14 Chem ist ry of Some Polymer ic Materia ls

11. 11 .

II

II o-oo o o o
~ O- Cll:- O- C O 6 0-CH 0 – o- c-Oc – O- CH , – O- Cv

URE 14,2 Th,1 midsect ,on of a fre ight lla ,n consists of al tern ating ,nierconnected ra ,l ca rs a nd ian~ ca rs It rese mb’e s the macrom olecular
~:l!wre of po lye thyle ne te, phthala te, whose d,ss1m ,la r un its may altemate regular ly o r 1rreg ulc1 rl y

The sub stan ce ha vmg such m:1 cro mol ec ul es 1s ca ll ed a copol y me r. Alt hough the
port io n u f the macromo lec ule shown 111 Figu re 14.2 has regularl y repeating u nits, a
copolymer may also be co mpo se d of uni1s tha1 a lternate 1rregu larl r.

When chermsts exam ine 1he three- dimen sio nal structu res o f pol ymer s, th ey find
tha r thesr chai ns of repeating units are in va riabl y cross -linked. Figu re 14.3 1llust ra1es a
m;1cromolccule in which one c hai n ha s amich ed itself to ano1 her cha111 by mean s o f a
cht mical bond. Plastics manufactu rers often attempt to intemionall y in crea se the degree
of cross-lin ki ng in 1her mosctt1 ng p las ric s. Th e resulting po lyme rs a re d ense r, and 1hus
stronge r and more durab le, than those whos e macromo lec ules ha ve un li n ked c hain s of
atoms. Cross- linki ng the chains wi 1hin mac romo lecu les also potentia ll y make s the
products manufac tu red fro m t hem more ela stic.

Macromolec ul ar c ha ms wi1hi n polrmers can a lso be folded, coi led, stac ked , looped.
or intertwined in to definite th ree-dimensional shapes. Although th ese co mplex co n figura-
uon> give pol ymers their uniq ue propemes, we req uire only the info rmatio n conveyed b y
thr 1r one -dunen sio nal patterns.

Pol>·mer manufacturers sometimes d iscove r that th eir products a re too stiff and brinle
for their inte nded use. Th ese undes irable feat ures often can be ove rcome b y adding
plast,m.er to the pol r mer. This is usua ll y a liquid th at manufacturers di ssolve wi1hin the

polr mer. Ir causes the pol ymer to become flexible by lowering 1he attractmn between
chr pol)·mer chains. The mo st common plasticizers are phtha laces (Sec tion 13.7-B).

The production of po lymers is a majo r activity in th e chem ic a l industry. These pro·
cmes :ire accomplished primarily by unique chemical reactio ns called add1t 1on a nd co,z.
densatJo n. The pol r mers rcs uh ing from th ese react io ns are ca ll ed addition polymers a n d
condensation pol ym e rs , respecti\·el y. \X1e review them independently.

flGURE ~4 .J A cross-hnke d polymer The colored c11cl es desig nate an arb,trary monomer. not ,is 1nd,v,dual
a’.c”‘s C•oss-l 1nk ,ngw ,thm andbetv-1eenmacromo1ecu’esg ,,e,;the polyme rextrawe ngthan d durab ,1, ty

cop olymer • A poly ·
mer produced from
two or more d ifferent
monomers

cross-lin king• The
p roduction of chemical
bonds in multiple
d imens ions w ith in a
polymer’s macromo!e –
cules, typically associ –
ated with its strength ,
durab ility, and elasticity

addi tion p ol ymer A
polymer resu lt ing from
the add it ion of a mol –
ecu le , one by one, to a
grow in g polymer cha in

co nd e nsa t io n po lyme r
• A polymer produced
by a chem ical reaction
along with a small
molecule like water or
ammonia

Chapter 14 Chem ist ry of Some Polymeric Ma t erials 609

14. 2-A AD DI TIO N POLY M ER IZATIO N
l’ol) st~ r,:-nr is ln example of :m ;1dd1t1Pr’. polyme~. _Ir is prod uct>d l,y tht polymC’n lJt10
ch e mo nomc-r SI ) rC’nt’, or ph<"n )' lethene. as follO \\ s. nor

‘i’ 1i1 1/ ‘if 1_1 – ~-t li 11 6-rn,,,, – -~6~d ~o·~i5~,,,
~-

The chemical fo rmu!J on th e left of the ar row .re present s styrene, the monorn er. The
mula on rhe right of t he a rrow represen1s a scc uo n of th ~ po lysryrene macromoleC\l] for.
portion of thi s formub reprcsenic-d w1 1~1 m the brack e ts 1s repea led ove r and over ~:

1

~

times , when· 11 1s a \!Cry largr integer). l he sy mbol — deno1n that the un it is (-
In the chrrruca! in~usrry, polymeri zation is initiat ed in a c~ nt rollcd fash ion.~::~

to mHJ.tt e polymenza 11o n 1s to use substa nces capa ble of forming free ra dica ls \\h 11
are exposed 10 hea t o r light. Examp les of such c hem ica l initia to rs a re peroxo.;n~
co mpound s (Section 13.9 ) and th e Zieg ler-N_a~ta ca ta lysts (Section 9.4 ). Once fr«rgfi:
cals are produ ce d by th e thermal deco mposi uo n of a peroxo -o rgamc compou d ·
co mbme wnh neutra l monome r molecules to for m more comp lex free rad ica ls r~i’r~
wit h othe r monome r mo lecul es um1 I th e supp ly of the monomer has bee n exhausttd

For 11lus1rat1ve purposes , co nside r th e po lymeriz.i ti_on of s~yrc nc mduced by fr« ~adi.
cals re-suiting from rh e d1 ssoc1auon of d1bcnzoy l peroxide. T his po lr me riza ti on occ h
means of a number o f mdepe ndem s1eps, so me of whi c h are repre se nted as fo!lo11,/rs )”

0 0 0 O< :c-Q,,) ,01,) 0 - 0 O·

610 Ch apte r 14 Chem istry of Some Polyme ric Ma terials

0

O ‘LCH,-C:)[0(,1
l’ol}m,·, frn tmcnt

O Cll = CI-I _-, (!,’.)

I’ lymcrfrJ_’lll<' nl

T
I Jn 1h r fi rs~:~:;:~:;•::2:;1;:r:-:y~);scn b~oJ m :1de 1s ruptur ed, res ultin g

111 ihe ~:.11 reac rs w11h a s1yrene m:1:.~~~e ical s. In thc s~on d eq uati o n, a be nzoy lpcrox)·l
fr« r.i

11
thi s frec radical re . I ‘ form mg a mo rc complex frcc radica l. In 1hc

rh1rd ((!ll;:;; r~d ica l. Add it ional s~:rss,;; _1 another mok·cul e of ~tyrene to fo rm ::i still more
co1npk x If . P )Ond thosc 1llusrra red add success1vcl y more unit s
to 1~ :~

~

1
:
1
h

1
;

1
,~;~O ~~; ;~~~;;~

11
ta~::i~~:

1
c~~:~

1
~
1
l~ng chain of th e polymer hJ s b~ n pro-

Jue Th e s 11bS t~nc e _pro d uced ~y , ht’ polymeriza t~o ~ of sty rene is calle d polystyrene. Th e
reptJtlllg unll m 1h1s pol ymer 1s th c followmg: i5rn,~
Po l)srpc-ne is 11 s cd cornme rc i3 lly to man ‘.1factu rc produc1s such :i s bru shes , co mbs, disposa-
blr ,offce cup s, t hermally _insu lat ed eqmpm ent, building a nd elecuical insulation, coaxia l
rdc\1sio n ca ble, co mpact di sk cases, yog urt cups, refrigerato r inrenors, and the peanuts used
in packagmg. For Se\’~ral of th ese purpo~ . po lyst)·rene is mixed wit h a foam -blowing co rn-
Pound during processin g and manufacturmg. The foa m 1s produced by blowing and entrap-
ping ::i va~r suc h as I, 1.1 ,3, 3-pe ~ta~uo_ropropan e within 1he polysty rene unu l ir hardens.

\'(lhen mrend cd fo r use as bu1ldmg msul au o n, po lysty rene some1imes wa s mixed w ith
the fi re retard.1nt 1,2,5,6 ,9, JO-h ex::ibromocyclododecane, o r HB CD, and product’d as
rigid panel s of foa m board. Dur ing con stru cuon projects, these panels we re po sitioned
agJmSt concrete or dr p\’a ll.

Be

I

C

H

‘\

Br – CII Cl!,
I I –
CH, CH ,
I – \.

CH , Cll – Br
– I

nr – 0 1 CI I – Br

\?’d
CH C/1,
I –
B,

I..’~ !\9,10 l ku bromoqdoJoJ«oln<: H Ul CO)

HBCD was also used as a fi re retarda nt when trraung consumer 1ex11 les like upho l-
11cred fu rniture and au tomo bil e cushions. Howe\·er, t he com mu ed use of H BCD in the
Uni ted Stares in an y mat eri al is questionable becau se he.1 1th concerns a bo ut its sa fet}
ha1 e bee n rai sed . HBCD ha s be en found to accumu la te in fatry 11 ss uc s a nd hum:in bre:rn
milk, pers ist 1n th e envi ronment , and kill aqua ric organi sm s at low co ncentration s.
:,.; Jt1ons 1hat :ire pani cs to th t’ POP s trea1y (Sectio n 12 . I 7 ) ag re ed m 20 I 3 to ban it s
fu rurr manufocrure a nd use. HowC\’Cr, whil e fig hting fi re s, e me rgency res ponde rs mar
mhJ lt’ HB C D s ince pr od uct s co nta ining HB CD s1ill re ma ins ,n rr si dent1a l dwe ll ings.

Polrsty rc nc 1s rec yclable. Its re-cycl ing sy mbo l is th e fo nul ia r a rr owed t r iangle e nclos-
ing th e number 6, benea th whic h appe ::ir th e lwers PS.

L~
PS

Sc 1rrJ I 0 1hc r examp les of add 1t1 o n po lymers arc pro vided m Table 14.1.

Chapt er 14 Chem istry of Some Po lymer ic Mat e ria ls 611

r MfiAitki
MONOMER
Ethyltn e

CC

Vmylchlonde

H H

‘ I C =- C

H H

A

H H

‘ I ;=c
H CN

Te t1ailuo rot-U1ylene

Sty1 e ne

0
M”hy l met h,cryl• t e

‘”•
CH1= C

c =o
0

‘ ‘”•

11+1-itiMf:iiiGMIHI

Eu mpl~ of Add1t1 on Po lym@rs

R( ,EATINGUNIT

Pol~et l’y ene

H H 7 H H 7 7 7 H H H fl
-c-7- r- 7-7- c T c- c c – c- , – ~- c

H H HHHH H HHHH~ I

—-r-Poly(vinylch londe_) _ – ~

-~-~-~-1-~-:-i_1_i_i_i_L 7 H
I I I I I I I I I I C- c –

1 HOH OH (IH CI H (IH (1~ 6
Po ly.crylomtr1le …__

7 7777 77 7777 77 11 7-7 -7- 7- c-7 – 7- 7-7 – 7-7-c-c-~-
~ N H CN H CN H CN H CN H

Poty(tetrafluoroethyle ne)

– c- c-c – c- c – c- c – c – c- c-c- c- 1 _
I I I I I I I I I I C j]

f ijjj ~j~jjjj jf
F f FFF ff F f ~

Po lynyrene

7 77777777 7 7 77 11

~

12io!6!o!aa6
Poly( met hylmtthacry late)

(H l
1
CH 3

1
CH3 (H J

1
0i1

– CH1-C- CH1-C – CH1-~ – CH1 – ~ – CH1 – C -011-

C = O C :::c O C O C= O C= O
I I I I

0 0

0 0

\ \ \ \
CH1 CH 1 CH1 CH 1 Ol1

Pcl)’lm,tl’lyl mtthyl,cryat,J 1s orodoc,d th,aadrt.oo polymerization of melh~ I m ttiiacrylatt , a submt’UI’,,..
r91hefoa….ngmo,ecu1arfof’fl”ua

612 Chap te r 14 Chem istry of Some Po lymer ic Materials

? ~-
C, H,-\ f-C”‘ – 2( H O ‘1

0-0

fritn byadd•ng 10 a molecu’e of methyl mtthilCrylate, .i Ot!’lloy’ Pt•<»¥ rid<.a ,n·t'41!M ~er zat ,on

1
(H,

C. “‘1′”‘\•:9
C•O

CiH -( – Cl-!_

N l.itt<'f ,ao cal ream wnh anott1tr mo'tcu't of mtll'l)'I methacryiate 10 prod~ ,n tven IM9fl frtt ,ad coJI

fH 1
( bHs-C- CHr C, (g

f •O
0

f “i
( Hz’-‘ ~ (9 – (~H, ·(-C.’i1

f”‘O
,,,

C C

~ 1 process repe.iU until hundreds or tholl\ands of t11t rtPfJbng ,..Ms are produced with,n the JNotrOmOlewie

14.2-8 CO NDENSATION POLYMERIZATION
Condensation polymers arc produced b)’ a chemical reacnon callt>d co11de11satton po/ym –
eri::it10 11 . A common example of the ir producuon mrnlves the rcacno n bt twccn certain
alcoho ls and organic ac,ds. For example, when a glycol is heated wuh a dica rboxyhc aci d
ISec11 on 13 .6), the substances combine with the stmuhaneous ehminadon of water. The
pol)·mcrthJt re sults ts called a polyesttr.

Consider the chemical re:ict ion between the monomers eth ylene glycol and succimc
md. The fim step m tlus reactio n is 1llus1ra1ed by the followmg rquauon;

OH

I

CIJ ,
I -lh “‘”

CH ,
I.
011

COO H
I
CH,
I -(

II

CH ,
I .
COO H

COOCH~C H:OH

f1\s)
COO H

,\ n 1ni.·m.:1.1t.11,. nul ,~,
3r,hm,r

The murmcd1a 1e co mpound rr sulung from 1his rcae11on ha s potrnt1ally reacu ve grou ps
•t bo1h ends of th e ca rbon –

pol yt stt t • A polymer
cons,stongofrecumrig
ester gro ups

Chapter 14 Chem istry of Some Polymeric Materials 6 13

r gl) ~ol, t 1imin J11ni; 111 0 mokcu lc, o l 1•Jtl’r .111d producing Jn l’lf11 more cnmplc~ mcJ1.itC”3sfollo11, : 111 tti f ()()CH:( ·tt , OH
C l\ ,

0 11 COOH
(H , CH,

-m – -11)

COOCH:Cll:01 1
(.II,

– h i
-01

UI: CH : CH : f H: .. 21lfli 11

COOH 011 COOi\ COO( I l : C ll: COOC H:CH1C001t

0 0

‘ C- CII -Cll, – C I – • \
11 -1-0 – CH:CH: – O O””””‘”ln”””” !I

Add 1t1onJI cxJmpks of some condcnsa11o n polymers Jrl· pro\Lded 111 T1bJc 14 .l.

•hMUiMMJ(P
;,;P~:a•~:t:~~~: :::::~f~=:~~~:~ ::::~:,~:;te~~i~•c;~:,•~:t:~~
1011sm.1t, u1tratt”°”‘ths(Ol”dto”W’.onpo,>ymtr12al>Ol’l ocnir. tq.,.

;~ :~:s :s~::,~Kh~ =~: :;;,d t~,::dt!~~;-<,:;\:; a7~:;,:: ~Od UCTJon of 1 "!O cc-0-coo .. ri

-::i~~,c … ; – OOC· Q–c oo H:0 • M10’1)

l•c~ •”
:

oo, Q;-cooc .. 1cH10 .. … 10..~

-614 Chapte r 14 Chem istry of Some Polymeric Materia ls

,O+ltfll
~!ACl~~TS
[‘~I trf q’y(OI

” ”
~o- C c – OH

“”
o ~ o c-0 \

O~ OH

0

!

fo ,,…,~ !dehyde

” ” ” I
11/11- ( – ( – (

H

A.:l PIC , c,d

ExoillmplH of Condens.at,on , o lyme rs

REPEATING UNIT

Poly(ethy le.,e te rephth i l~te )

o : i o~~-0; o-i :-oF-0-
Ph er,ol-fo, m~ldthyde

I

,A-16 ~-k¾-oo” ii); ;OOH ~-y H OH H I y H Oh H y H
H – ( – H H – ( – H H-(- 1-<

‘ I

Uruform, 1denyde

Nylonf>.6

H H H H H H H H OH 7 H H O l H
tN- C- c- c- ~- c- c- /, c- c- c- c- c- c – N-1 I I H H H H H H

Ch apter 14 Chem1~try of Some Po lymer ,c Mater Ial1 615

l I

j I
l

11.1topolym1nz.1t1on
• SPQnt1nf’01.1S
pe!ymer1zat,on

In hibitor • A11.1b1Un(t
01m,xtvreof11.1bst1n

i\ wmmonh c-iic,,imtcrcJ pol}C-)ttr i~ d1c-11)1lguc–1111 ~trr pol )k th)l c-tk ll’rc
11\0rc- cummo nl} l..no11n .,s 1′ 1:. 1 r, Pl:T, or 1hc D1iPom 1radr11u,k :\ l)lJr. l
tor thl· rr0Juc11on of PET£ 1~ notC”d 1n Soh<"d Exn,1~<· 14 .2: . l'F I [ I\ u._J 1 :i 1qJe r:mg<' of mJ us mJI Jnd consumrr product s. It 1s prc-d mJnufJstu rin gof p!J )l!C bonl~Jnd fib(rs. bm 1t 1s also us.ed 10 m,1nufoc and com pu1e r 1ap,:s: ).ulb.:•Jt ,Jil ~; 1c k phone Jnd tltctn c cable wires; and of fuo J p.1c bgm g hl..e l..c1Chup and musr.1rJ ,:omamcrs.

angl ~~]1~~r~~t~;1;~;c-~:~~;~:lt.’~~:~e::;~ i:~~~~l:~j;;~~sl~:cie~~~:~ ~~l~;I is an arro11~ tn

Lt
PE1t’..

Co..-;i -Cob no” recicles th <' PET£ tm•d 10 manufacture the plamc bottles th,n umnssofidrmks. con.

A polyc-s rn 1s not the- so)r example of a co ndc-nsa 11on polymc-r. In this chap tc
~h Jll note th e- propc-mc-s o t pol yacr yb1111de (Se-rnon 14 .6 -C), forma ldehrde -h~ \\c
pol r mers (Semon 14.8 ), and pol yu mhan c-s (Semon 14 .9 ), all of ~h1eh are prodtd
as condensa ti on polymers. ccd

14.3 AUTOPOLY MERI ZATIO N

: ,~ i: i~i~~~~:s a:1~;~r!~:1;!t~onnd:fg:~:t:~~1~:a; .:~h~~ ~~~~~’;t::1~t:•1n:r :~to~ .
ma rise m tempcnture or prc-ss urc-, which mcrc-asc-s the nsk tha1 the vc-ssc l may ru~;: 1

The autopolrmc-nzanon of a subs[ancc- can b( prt\·cntcd so the- substance can uln~tdvbt
uSC”d for its mtcndc-d purpose-. Whc-n the- substallCe 1s gaseous, autopolymc-nZJuon is ~d
by the addmon of rutrogcn, c:irbon dioxide-, or othc-r inert dilucms. Al th ough men oompour,c1s
also may bt used to dtlute liquids tlut art prone- to Jmopolymc-nzc, the- common practice wd
by chcll1Jca! manufacture-rs 1s 10 add an mh1b1tor fO them. A$ the- nJ mc- implies, an inhlbitor e
a subst:in.cc thJt che-m1c:illy reacts m such a fa~luon as ro mh1bu, reta rd, or stJbi hzc- the Lqlld
agam st autopolymenzauon . i\ popubr mh1b11or 1s tert-burylhydroqumonc.

OH

Q-C!Cfhh
011

ru1 1\ui.’lh)dn.>.jJan(>fl(”
~, I I l lHll,no,,,,.J,ol

Although the-re IS not a cons1s1c-nt mcchamsn1 by “h1ch subs tances autopol )·mcnu,
so me- are m1t1atcd by the reaction of J pcroxo-o rga mc compoun d th:11 re-s uit s when 1hr
su bsrancc- re-acts w11h dissol1•cd atmnsph<"ric oxygen. In this mstance, 1hc- 1nh1b1 1orsdtcttd for rc-1a rdmg autopolymcnza11on 1s an Jnnox1da111. wh ich 1mmcd1a 1c-ly rC3C IS w11h 1hr peroxo-orgamc compound as II forms.

DOT regula tes the transportauon of subs1anccs 1hJt :ire- prone- rn auropolrmerw ·
uon. some examples of which are pro11ded 111 Table 14 .J . DOT also re- quires shi pJl(n io
md1ca1c rn the ba sic shippmg dt”scr1p11on thJt 1hr1r products have bre n StJ f. 1hzcd agams1
autopolymc rization. Exampl es of the bJs1c ship p111g nam rs for such sub, tances are “tthil
acry!J te, >tab1hzcdM and Ml’1t1)’lidfncchlor1dc, s1Jb1lizcd.M

To fore-warn cmc-rgc-ncy responders of the presence of .1 sub,1ancc thJr is mo;.:epubk to
autopolrm<'rtZJIJo n, chemical manufac1urcrs an d user~ so metimes msert J P m 1he bottom quadrant of the h:iza rd d1Jmond pus1ed m the rc-b·am s1oragr area . In 1h e E.mrri;r11cy Rfjpo,u,

616 Chap1c-r 14 Ch t m1stry of Some Polymtric Mater ials

h ampl M of Monoml!rs Th•t Autopolyml!nu Unl ess
Effect ive ly St.bd,z~d

p,4Qt1O MER SHIPP ING0ESCRl’llON

,.,ry1onou, lt UNl09J, Acrylon,tro le. n•o,l,zf’d, 3, (6 1), PG 1 (Po lson – 1nh.il11t,o n H•iMdl

o,1oroprtne UNl 99l , Chloroprt ne, 1t•b,l, 1t<1, J,(611, PGl(Po1!,()(l - lnh.ila11onH1urd)

flh~l <1(rylatc UNl 9 ll , Et hyl •cryl,ne, IUb,hzed, 1, PG 11 {Marme Po l!ut.int)

110 prene UN1218,1soprene, 1tab1h1td, J, PG I

~•tthyla

~•ethyl methacrylltf UN 1241, Methyl mt1hll

Styrtnt UN20SS,Styrene, 1Ub,h1td, l , PG ll(M,1nne Po ll1.1t1nt)

,f,r,1l1CC”llllt UN1301 , V~ stab,l+zf’d. 3, PG II

vnyt bromlde UN108S, V,nyl brom 1dt, 1t•b, hztd, 2 1
v.rrytbuty1 a1e UN 2838,Vmylbuty•,tt,ltab,hztd, l,PGII

l/,nylc.hlo11de UNI086.Vinyl

v,nylfderoechlor,dt UN1303.Vinyhdtnt

Cuukbook, a subst.1 ncc- susccpnble 10 autopol) mcnuuon 1s 1dent1fic-d b)’ the- ms.c-rtmn of the
kim P followmg rhc 11.m ng of a gULdc- numbrr m the yellow- an d blUC”-borderc-d p.igcs.

14.4 POLYMER DECOMPOSITION
AND COMBUSTION

,\ lost prod ucts produCC”d fro m na tu ra l and srnr hcuc polymers a re combui.ublc when cx~d
roln 1putton sou rce . Thei r combust ion 1s assoc1arc-d w11h the- fol10111ng genrral fc:irurcs:

Polymc-ric products o h en mdt and thc-rmally dc-compo~ mro t he monomers from
“h1ch thc-y we- re- made- or a mixtu re- of simpler substances.
The sur fJc c- s of some polymeric produc1s tend 10 chJr as thq· bum.

I Burmng polymeric produc1s rele:1sc cons1dc-rablc hC3t .
Burning polymc-ric products can e1o h c l’Olummou;, amounts of smoke, carbon mon –
0~1dc, and other h;1zardous gases, vapors, and fumes.

The mdtmg of po l) mcnc produc1s ar a l}’J:nca l fire- scene 1s a>wc1a tcd w1th bo th bcncf,c1al
Jn d drtnme 111 Jl c-ffec1s. The- md 11 ng oficn ca usc-s the pol)mc-r to drip from LI S source, as
from ce-1ling hie to an undcr!)’1t1g floo r. Dnppmg molten poly mer closely rcsc-mblcs dnp-
ping ho, ca ndle wax . The- drippmg sef”\·cs as a cooling mrc ha111sm, removmg hC3! from 1hc-
1mmc d1Jrc- si te of combustion and hmdm ng 1he contmued cumbusnon of th<' pol)mc-r at that s11c. Howe-H r, when polymers re-mam m 1he fi re zone, 1hcy begin to the-rmally dccom- po>( 111 their mohen st at<' . Then, 1hc-1r dC"COmposltlon products 1gm1c and the fire- spreJd>.

lkfore their 1gnL11on, polymers frc-quc ndy undc-rgu thermal dcgr.ida t10n 11110 s1mplc- r
chcmJcal spcocs: th3 11~ , \\ he n they arc cxposc-d to brat, pol)mcrsdrcornposc- mtO rc-lJti\c ly
11m pln submrnccs. T he dc-compos1uon of umque organic pol )’ mers occurs h)· d1ffc-rcn1
mr-c h.1n1sms, $e1er:1l of which in1·o h·c- sc1n1on of the m;icromolecular chJ1ns . The follow –
ing t”‘o t)rc-s of 1herm;1I decomposmon are charac1cnsnc of how pol)mC”rs dc-

When hca[cd. some pol )· mcrs prcdomuu. ntl y produCC” the monomers from wh1ch
they \\ne mitiall y produced . The)’ are said ro dtpOl)mtnu, and the dc-co mpus111on
r rocr~s 1\ ca lled d t polymtrlzatlon. for c-sampk, 11 hc-n pol y[ me1hyl mf lhacry !Jtd

d t polymed nt lo n
Thtthe1m,1\de

po11t ionproce11aurin9
wh,(hllpolymtf pro
dL1

Ch apter 14 Chemlnry of So me Polymeric Mat er 1al~ 617

nomtnon

FIG URE 14<1 i-u1•.wa:Nitrrou9s1~1~'°'101;,,..• 9,t'lr-lt> lotht> (;
ol>e,.omtnon knoY>””” .i !J\P”IC,e• ta~ ca~\,t’\ t”C’ tMrm;,I Ot>

:,~~~::~:;:’:~:lio~~~: 1~~~:tt~t>t~~/:: ::.i;;t:~,~~ 1~/, ; ‘°\
DC ~1 of O’; a~o ,., .,, w t’l the 1urround “9 .;,, ‘,l/l>tn a

1humally decomposes, 11-. monomer. meth yl methacrrlatc, accounts for 91 to 98
by ma~s of rhe subs tances produced. The same 1s true of poly (ethylene 1ercphih \
\X1hen heated, 11 rr,u1 s mto the substances from which II was produced: tereplt~tt~? :;;icl~~:. r1h yle ne glrcol. Polrmas that depolymer1ze are desirable candidates fo~

When certain mhcr polymers are heated, they produce an array of ga~us dccom.
posmon products . For examplr, whrn po lypropylene 1s hrarrd, 1t drrompos« 10 fonn ~~:~:~>~{- ~~l~:;;~~-r~~~1;;h~~1~;~~:;::~/ropene, 2•methylpropenr, ] • and 2-pcntenc,

The vapors producrd by therm al decomposmon im tiall)· diffuse to the surface of the
polymer, where the y mix with atmo,;phenc oxygrn and 1gn11e. As thr heat mcru,c-s in

:~~ehn:
1;~;~~~;·:~:t~ra~;~ ~.~;;:1;;:~:: ~:,i:~•:t a:: t:~:.cc umu late dmibm,

Heat may also be- conduc1td or radiated through a polymenc m:urna l, therebi· caus.
mg thr polymer to decompose at a loca non isolated from th e heat so urce. Consider the
secnon of a wall shown in F1gurr 14.4 . lt 1s cons tructed of wooden suppon beams to
whJCh po!ymrr1c panding has bun affixed. Although thr hear from a fire imping~ on
only one side of thr wall , 11 can conduct or radiate through thr wall, causing the po!Jmci
m the- p.mdmg to decomposr. The mix1urc- of combusuble gasrs subsequently produrnl
b)’ thermal decompos111on readdr igni te~.

Tius gene ration of flJmmable \’apors at a loc:1.11011 isola ted from the sourcr of ltw kl
associated wnh fl asho ve.r, the phenomenon largely respons1blr for 1he spru d of for
from one room m10 :rn adrarent room. At flasho\’er, the enure conums of .1 room arc
1gnaed simultaneously by radiant hrat . This si tua tion mJkes li ving conditions wuhm iii(
room untenable . SJft cx 11 for res1drnrs 1s impossible. At fl:i shon•r, room tempcr.uurrs
typically range from approx1mm·ly 11 00 ro l4 70°F (-600 to soo•q .

Fires post spec ial problems in IJrgc public buildmgs that h:i \’e brrn conmucttil m
pJrt from plJSllc p rodu cts, smce the pol ymer s in 1hese produ cts usuJ ll y burn d,ffrr•
cntly from burning wood o r other n.nural mJtuials. T he thermal charactcnmcs of
some common pol ymer s in :i1r are pro\’ 1d rd 111 Table 14.4 . ny co rnpa nson, ha rd11 ood1
self-ignite 111 a1ra1 ana,·r rageremprrJ1 ureof78 l “f /416°C ) andha1e:rna\eragehcar
of combustion of 8500 Btu/l b. ,\[th ough hardw oods an d syn t hrt JC pOl)•mcrs bfg1n 10
burn at approxtmJtely the sJm e trmprra1urr, po lymr rs like- pol)·cth )’lenc, i>0l>11 rop1I·
cnr, and polystyrrne emu morr than t\.\ice JS much hra 1 :as ,h e samt” :amnunr of bum·
mg wood.

618 Ch,p ter 14 Chem is try of Some Polymeric M1ter i

jtS.i!itil Thennill Charilctensucs of Some Common Polymers
,OlYMER
Pol)ethylent
e, .ghdtnl•tY)
pol)·()’OPYlfnf

Poly1tyrtnt>

Pol)(l’!’ethyl
mtth~r,t e)

p0i)'(v,nyl
,~10,,d,J

SPECIFIC DECOMPOSITlOlj
M.NGE

644-6l4′ f
(.340-440′ 0

626-1/0′ F
(H0-410′()

57l-7S2′ f
(1()0..4~•o

31S-57l’ F
~ 0-JOO’ C)

192 – 572’F
(200-JOO’C)

SflF•IGNITION
HM PEMTU~E

662’F()SO “C)

H4-770’F
(19{µ10’0

914′ F(490″0

842’f(450″0

8 51 ‘ f(455’0

HfAT OF
COM8 U5Tl0N

20,0S081u/lb
….j….(46.SOOkJ!kg)

19,8-00Btu/lb
{46,000kJ/kgJ

18,1008tu/lb
~ g)

11,2 108tu/l b
(26.000lulkg )

86208tu/lb
(20. 000kJ!kgl

14.4-A THE CHEMI CAL NATURE OF lliE GASES AND VAPORS
PRODUCED DURING POLYMERIC FIR ES

The fatal111es thac occur at fire scrn« ohen rrsuh when indmduals are exposed to thr
&~K’S and va pors produced during 1he fires . Burning polrmers product n1a s51 \·e co nccn•
crJuons of carbon mon oxid e. With in an rndosure, ca rbon monoxide and other gases soJr
10 hfc .•hrearrning concentrations wuhin a mJtter of s«onds.

fires mvol vmg hurnmg po lrmrrs can dfcct arr:a s far removed from where thr fire
ong1na 1ed whrn hot gases and 1hc rmJI degr:adauon products tra1·d by co n\·ectmn through
,rnulJuon sys rrms, tras h chu1es, and smular oprnmgs. Ahhough 1h1s mo\·ement spreads
the fi re, 11 also causes people- to br unsuspec1m gly exposed to toXJC fumes gencra1ed else •
.,.hcrc w1rhmabmldmg.

The burmng of products made from S}’ nlhcu c pol)·mers often producrs a mixture of
s.i.es and fumrs different from 1hat generated by th r burning of nonp lJmc products. Car-
hon monoxide- 1s m ll the most prr\’a lrm gas a1 a fire scenr. but other gasrs associated
wnh bummg pla stic s arr also produced . These include hydrogen c hl onde, ammon1:1,
htdroge ncyamd e,sulfu r diox1dc,andmtrogcnd1oxidr.

Al a firr sce ne, the or1g.m of the muogenous and sulfurous gases can bt tracrd to 1hr
,hem1cal na ture of 1he pol ymeric materia ls that ha1·e burned or undrrgone therm;il
dcco mpos11ion. Thermal decompos111on occ urs pnmarilr when the palymrrs a rr rxposed
to the hea t rm m ed durmi:; slo w-burnmg process.cs. The pol)’mers that produce hydrogen
q~n 1dc, ammonia, mmc oxide, and nitrogen dioxide arc mtrogcnous organic compounds.
lhcy arc na1ural an d symhcuc polyme rs that ha\C’ one o r more of the funrnonal groups
hired 1n Table 14.5. When they thrrmallr dtcompose, h)·drogcn cyanidr and ammoma
ue producrd: and when thr r burn 1ncom plctcl)’ and complrtelr, mtric oxide and nitrogen
d10~1dr are produced, rcspectll’d)’.

Pol)·mcrs conuining sulfu r atoms usua llr arc namral polymers hJ\’IIIS an anunal ongm.
llmr non\\arcr matter 1s composed of proteins, which in mm arr composrd of amino adds .
A!thoui;h th ere Jre 21 ammo acids that nu ke up the structures of ne;ir] y all pro1r1ns, of
concern hnr arc onl)· 1hr two “hose molecules contam sulfur atoms m their composmon:
mcth1onmeandc)>tcmr.

0

Lil i ~ – Cll1Cll1-1H \
NII, Oil

(J
I

H’)- UI: TH-C
NI I~ 0 11

.o m,no .1eld My
carbo,;yh<11c1dha'llng tht - NH1 9rou p olatorns

Chapter 14 Chem imy of Some Polymeric M;,terlals 619

• mid• • .l.no,9;,n,c
compound whose
mole

rutnl 1t • AAyorg;,no< compound whose 9ener•l ch,m,c;,I formul.i,s R--C::::C.',, whue R,1an•rb,tr•ry •l~yl Of ,1ry l group

n itrocompo und • Any
o,g;,mccompound
wh~9enu• lth tm•i• I
formu l• 11 ~- NOJ,
whe1t R 11 ,1n ,1,b ,trary
1lkyloruylgrouo

MfthitiW Some Nitrog•nous Org.ilm c Compou n ds
CLASS Of ORGANIC
COMl’OUND

Amide

fU NCT!ONAlGftOU P

CS C

Nitro!e, orcy,n,dt –C:::11

N,1,ocom pounds

EXAM PLE

CH,01,CH,- 1,>i
1

P.oP) •””·””- or
111,,,,~c.!’:’o~~,

,,0
(H i- 01 – (

I ‘ NH1 OH

I } A :,,no(lfo~’IO~a,:,d
(1-;iCH1-Nc:C==Q —
ltt>~I >O()’arw•,

C~ C~r~-
n au1ylntr•1,

N ‘)lor, ,u r.0< ~•00•0•••,.-, 0< V,n 11C)-ao•Cr

Becau ~e sulfur atoms are component s of these ammo Jc1ds, th ey arc also consmucn

ti

of th e promns b1olog1cally produced from them 1n leather, \\ool, and anunJI hw.
Th eir thcrmJI de com posmon produces hrd rogcn rnlf1dc and am monia, and thmcom-
bus11on produces c.i rbon monoxide. carbon d1ox1d e, ml fur Jmx1de, mtnc ox1de, mtrOj;rn
dmx1dc,a ndwa1er.

Anothc-r tOXIC sulistJncc- whose prc-sence ha s been detect ed ,n smoke ts the un >o1 1u
r.itc-d aldehJd<• known as Jcro!e1n, o r 2 -propc-nJl. lt s chcm,c,1] forrnul.i ,s Cl li '-- C!lCHO

0
CH ~ CH – t.

~crdnn,! l’hJ’<"'ll l ~,t\l,, 1IJ.th, I

This 1s .1 pungent -s mc-llmg, mten…-1) 1rr11J1mg IJcr1m,1tor, ,\ ]-m1nutc- cxposu r,;: roJn au
concc-111 ra11o n of 1 p,1rt per rm!l1on causes na s,1! and e)e 1mtJ11o n. A con,;:cntr.mooof
acrokm m air r.1ngmg fro111 1500 to 5000 pan~ per m11!1on hJs Ix-en est.1bl1shcd as 1ht
lc- 1h al dose to IJbo ratorJ’ .1n1m.1ls. Dunng World \'(1Jr 1, ,1Cro lrn1 wa~ used offrns11c-\p1J
l,1 cr1m:1tor (Senion 10 .9-Al.

620 Chapher 14 Che m1nry of Some Polymer1C Mattri.tls

14_4.s SMOKE PRO~ UCED DU RING POLY MER IC FIRES
fhc chHJCtU of the smo c- producc-d during fires 1moll1ng polrmer,c mJicn:1ls ,·Jnes

h ihe chw11c.1I nalufc of the po lymer. In p,m1cu1Jr, the- amount of smoke produced m
;~ 111 , 0 [v1ni; pol rrncrs nude from aromJt1c mono111en is rypicall r for gre.itcr 1h an the-
moun t producc-d during th e burning of polymers made from al1phauc monomc-n. ,\ fire

~~ 1011 1r,g 1nJ1cr1Jls producrd from pol}’st)rc-roe, for msi,mcc, produce, coruider.ibly mo rc-
j(IOI ,lwn one uwoh•mg mJ tena ls pro.:luctd from pol)tlh)lcne.

i\> \\:I S first noted m Section 10.9-C, the urban pu 11 culates rn smoke :idsor b
10~1, gJStS on 1hc-ir >urfo_ccs. Wh en smo ke- ts 1nh.1!ed, 1hcse paruculates sc- rvc JS th e
,·chic ks thJt drJw toxic gasc-s mto th e bron chi and lungs . Because considerable omoke
11 produced du rin g th e burmng of m.1te ru ls producc-d from aromauc monome rs, 1h C)’ rost a greater risk 10 one ·~ hc-a hh compu c-d to materials producc-d from al 1ph:m c
mo nomtrs .

14.4-C CO NSU ME R PRODUCT REGULATIO NS
PERTAINING TO TEXTI LES

Pol)mc rs hJv e be-en used 10 manufacture hundreds of different consumc-r products.
&cause most pol)·mers burn, the consumer products m.a nu fac t urcd from them a rc- now
r•llu ated to dc- termme whrihc-r the l1kc-hhood of their 1g111uon 1s delare d o r c-l 1mma1cd
.. ~en their fibc-rs ha\·e been lrtJfcd wnh fire re1ardants or flame-proofing age nts .

Congress has d1r(“(“fed the CPSC 10 reduce- m1 unn and deaths cau sc-d by consume r
rroduc1s 111 a 1·arrc-ry of sc1 ttngs. In resporu.c 1U th 1> mandate, CPSC pubhshc-d a siaodJ rd
lt !6 C.F. R. H 16JJ. \- 163J.JJ, which aims to mm im1u or delay flasho\’Cf durmg ryp1cal
111Jttfl:sslbcdd1ng fires that occu r wnhm the- home. In Figure 14.5 , the comparison bctv.een
ign111ng 1wo mJt!ressrs. one manufoc1urc-d con1·enuonally and the- 01her m:anufaciurcd m
mord ancc with 1h r CPSC s1andard, is demonstrated . It 1s apparen1 1hat 1hc mamrss
11Unuf.1cturc-d m acco rdance wnh the CPSC ~tJnda rd is mo re dc-sir.iblc as a co11sumcr
rroduct. b«-ausc- exposure IO an opc-n fl.1mc pro1·1 dcs 1he occupants w11h tim e- to disco1·cr
1k fi re and cscJpe from the- home .

Figure 14.5 also 11lusUJ tcs thJt although treJtme m procedures m.1i· 1mpro1·e the !.afc1y
of products for consumer use, 1hey do not lot all)· cbmma!e thc-1 r flammabilicy. After poly-
mmc fibc-rs hJ1·c bee n lrcated, the producu made from 1hc-m still bum, cspcc1,1lly when
tht) Jre c-xposed to the mtc-n sc hra1 cxpcncnccd dunng maior fires. Howe1·er, 1re::ucd con•
1umn produc!s JrC more res1sunt to 1gm11on and more prone 10 scl f-ex tmgmsh once fi re
bJ1bcc-nm111.1ted.

51J1e an d federJI laws req uire manufacturers to pro11de co nsumers wi th matcnJl s
1h11 arc- unlikd)· to ras1ly 1g nuc-. Their combmed use ha s helped re-duce m1une> when
rlm1n and 1e x11lcs arc- 1molvc-d m fires. The CPSC hJs used th e- legal autho m y of th e
fl•m mabl e Fabrics Act a nJ other ; 1a1u1es 10 respond 10 pubhc conce rn over acc1dcms
m,olvrng th,;: use of products like hrushc-d r.l )”on 111 high-pile S\\ CJ!Crs, anJ ch1 ldrcn·s
ro\\boy chJps 1ha1 nJ~h -burn 1,hen 1g111ud. The- CPSC now rcqu1rc-s manufacturers to
1ub m11 sam ples of apparel fJbrio like ch1ld rc-n ‘s slce p11 ea r to :rn 1gm11on tcs1 and a rate·
of burn 1es1. The use- of 1hes, 1ests al.o applies ro the manufoc1urc of C’:lrpc ti, rugs, Jnd
oihrrhomcfu rimhrng s.

14,5 VEGETABLE AND AN IMAL FIBERS
,\bn)” com111on tcxules Jre produced from nat urall)· occu rrmg 1egc-tabl, and anm,.11
hkn . Cotto n and lin e n art’ c-xamples of 1·rge1Jble f1bc-rs, whc- reH wool and silk arc
tl..l mplcs of an1m,d fibe rs. These na turall y occurring fibe rs mJy be usc-d to produce trx ·
ulrs, or 1he r can be chcm1eallr altered to produce- symhc-uc fibers from “•h,ch th e texuks
ire produced.

riamm a bl• Fl b ri,s Act
• Thtfe<:1e r1 l 1tatut e lhiltmpowtrilht Con1 .,merProduct1 S1fety(o mml1slo,,to ut1bh1hflamm 1b lhty 11 1,idardslorcioth,ng te,rtl!~ a1wella1lntt- , lo,fu,n l1h lng1,l n< lud- ln9papu,pla1tic,foam 1r,d o1humatt,.• l1 u1ed 1nwt•ong ;,ppa,tl•r,d in ttrio1 furn l1h,n g1

cotton • An’1.,,. ll y
occurr.ngf1btrolveg –
etabltori9 ,r,

hn en • Thenat.,,,1lly
oc,.,mngf tbtroltht
fluplant

Chapter 14 Ch emistry of Some Polymeric Materia ls 621

f lGUAt 14 .:; i’I th 11 ” ~’ mt’>\ two md’ltresses 4’f VT11;’t.intou1ly e , 001, 0 IO an o~n-f ,1-,,, 9n \JOII IOU’tl
10 \’T’ua:e t~e bur’l,ng o’ ,.,3\’.

a’. 16( f~ §~ ‘ 6 3] 1-16]] l] l\burr1or,,.,010,,1at a no1cub v 1’0-“‘t ‘9’°”””‘J’ eco,-p.i·to lO ll’tbU”‘>
r gr •t e ofU,eunttu!fO rT’ ,1ttre11a11reOOt1omoltnel,9u•e ,Ccurt01)-ol1n,vs (o,,-l’>o.1..og10,,0()

622 Cha pt e r t 4 Chemistry of Some ?olymenc Mater ,als

jb-i11tiW Some Anlmfil •nd Vegeuble Products
,~0 ouct
cotton
(otton, …-•1:e, o •ly

cotton. wet

~~~~::•~~~ ‘::a~~”‘• veg tt•b le

\\1 1PP\N GDES(IIIH!ON

NA.l}f,\, Cotton, 9•

UN1]6.4, (mt on waste, o •I~. 4 2. PG I I~
UN1]6S, Co:ton . … “tt.t2 , PG l!I’

UN1l7l, 1,ber1, •n 1m11, 42, PG \1I

U”-11]12, f,b er1, ,·tgtuble, 4l , PG III

!Df”• ‘”‘get•b le , O’)’ UNll60, F,btrl, Vt

1 Ct,:i;, tab r

UN UH. ~,btn, Vt

UN\313, F,be,1, 1ynthet,c. n 0..1 (

UN131l, F1be1l,tynthet ,c.no \ (conta,n,ngvtg •
._eu b\eo~ Gm

UN13S l , f,bers \mpregn•tedwithwuklyn •tr•led
n <1roct \lu\ose, nos . 4 1, PG III

UN\lS}, lllOUCS ,m pr tgnn<10 W>\h wukly nitt•l<1d __ n ,troc.t ll ulo,e, no\, 4 I , PG Ill

, ~ 1•tura1eO o,Hrutl!-d incomplf!i,ly UN1319, ” “P” , un\.iltu, atta o,I \fu \ed, 4 2, PG Ill
dJ,ed~ndudingcarbon,,..per) -l.–
~ s\t UN\381, WoolwHIR, Wtl.4 2, PC. 111′
‘Joo \lQl’\0>1 «1r.,,,po,tat,o,,onl>j an ,.,at«

‘for lr

As the) occur nJturall)’. vegc1Jb\c :md ammJI hbcrsoftcn arc m,:,:.-d with combusublc
Ol\s: for rx1mplc. cotton contains cottonseed 011, and wool com.uns \.molm. DOT rcgu-
liits the trJnspouat,on of the vegetable and animal fibcu listed m T1b!e 14 .6 as haurd –
ou s nu tc r,Jh. \’\1e n0IC’ the propemes of wmc common fibers :and pa)’ 1;penri\ au en twn 10
1~mco1nbumb!cnature .

14.S•A CEL LULOSE AND ITS DERIVATIVES
The po\11ncr th.II rcmJms when the narnnl bmdmg agent 1s rcmO\ed from \H)Od and
other plants 1s ca lle d cellu los e . h scr\cs JS the pnmJ.r)’ struClural co1nponc.m of 1he cell
11,111 m plJ111s, a nd 1hus 1s g~nu;ill)’ rcgJrdcd as nature’s mos l 1mpor1Jnt polymer.
Wood I\ a pprox,ma1cl)’ SO% cellu lose by mus, whereas cotton a nd \men arc ncJrl)’
I00 °occlluln sc .

Cellu lo se fibers a rc de rHcd from cotton and !men. Cotton comes from any of fou r
•~•~ of Gos~y pmm tl1Jt grow m warm duna.tn 1hroughou t the \\Orld . To produce 11 J.~
2p m. r,1w cotton 1s first boiled ma d1lmc sohmon of sodium h1dro..,1dc IO rcmo,c .111)
V. lX 1h.1.t n.11urallr .1.dheres to the fibers . The n, 11 1s blcJchcJ w11h ch\ormc. ,odmm hypo-
chlonte. or J. ~11111\ar substance and pJs.cd 1hroui;h a vat o! d1lu1ed ~uHunc JCtd to ncu
112hre an l’ rema,nmg alkahnc- m-.ncrt:i\ -, , Finally, the cotton 1s wa~hcd “11h w.1.tc1. ,\t ch,~
ro1n1, n , s re.id )’ 1u be spun 11110 a )”arn 1hJt n1J)’ be WO\cn ,mo dmh.

u Uulo!.t Tht\ub
1tance 1hatlo,m1tht
ce llwa ll1ol1llplant1

I\

Chapter 14 Chem ;nry of Some Polymeric Mater,ah 623

l inen is m.”.Hh rurccdluloS( . Its fil'(“rs arc drm ed fro m the M.1l k of th(‘ fl J :.: plJnt l,,r
uMt.Jti..,wmm, . Lmc n fi ber.. a rr among t~e s1rongrst nJturJ!l} occ:1rnng fiht rs. l inen fa lo.’i!
:i b,-o rbs mOl)lurc fJsier rh Jn Jfl}’ oUlrr labr1c: hO\Hl ~r, lmcn lac ks rrsil1enq , the abiL bit
\ pn ni; Nck 11 hl.’n mrtchc

Tht diftcmi.:t” t-r r,, cc n the ph)’)KJ I propcm es of co non a nd hnc n Ii JSSOc iar cd .,
t he nJ turr of t he ir fi brn. Wh;:n (‘!IJll ll nr d under a nu c ro sco pc, 1nd111 d uJ[ ca rton fi:
n:)rni bl c short, rwi srrd, fl Jncne d tu be~; lum1 fib(: rs re semble long trJn sparem 111~ l~
hJ1e ptnod1c 1unc tLons fo r cross- lmkmg. 1

Cott on is commc rc,Jil )’ a1Ji1Jbl r no t onl y III it s natu ral form bu1 also as rncrccrurd
cotto n. C o ll on fib er s s11cll 11hen tht)’ :ire 1mmrrs r d Ill 3 conct”ntrJud ~oluti on of
sodium hy drox id r . a proce ss called 111ercerm11g, after the di sco\ere r John :\!ercet \t1ic
each fb ne ned cJrbon fi ber 1s rnercer11ed, 1t btcornes rounded and more lus troui
acquires addiuo nal s1rt ng1h . D) cS penetrate fabrics made frum rmrce n zcd cotton more
ca sd y t h.rn tho~e made from untreated cotton . :\lerctnzed cotton ca n be chem ic:,,U
trtatcd 10 produce fabrics rhat are Mmkleproof, as \ie ll a s fobrn::s 1ha1 can bt Was~~

:~iti r~~:r:
1
‘ 1! ;;~hd~:;· f:·;~~;slet~a~::~0 ~0:~c~~~:11~,c a~.:;;~~~~l~sc~~~~:e~.1:t~~f) n-

suc h J S 50% co tt on, 50% 1J crylus.
T he c hemi cal formula of cellulose often 1s a bb rc1·1a 1cd as IC~HioOs)

Jt C~J-I-O110H 11],,. wherr 11 range~ fr om 7000 to 12,000. The following st ructure 1~ r:
5c-111 s the more complc1e chemical formula, 1n whic h carbon atoms arc locJtcd 31 th,
mter’>tctm i; lm ~:

H H II
CH::OH O Cll:011 0 CH :_OH O

1o~\ 0 ~ \ .o II H 0r-HO~ HO~ HO OH
H Ii H H H

The repe.mng unn ~hown m 1h1 s ~1ructure LS a substance called /1 -glucose.
When mggcred bran 1gn1uon source, cellulose and cdlu losic products bu rn \\ 1tho,n

melt mg. but the )’ do nor bum re,1dil y. Because burning cdlulos1c ma rcna ls arc d i » A
fi res,ther rourmdrare cxunguishedw1thwatc r.

There arc n-vo ahcm.1mc p.ithways by \\ htch cellulose responds 10 the apphcaoon of hm

On C)Cposurc w tcmpcrarurc-s less than appro)C1matd)’ 570″ F (< 300' CJ, ccllulQ;t dt"polrmenzes and elimma res watt"r. As the dehydraoon ocwrs, a s!ow-burmng or smol- derin g ch,ir forms 1ha1 mar ult1matcl)· conl'er r 1mo ash .

On exposure w tempt’raturc-s greater than approximJtt”l r 570″F (> 300″Cl,”llu·
lose rhcrmally dcgrJd~ 11110 a black gooe)’ tar. When this goo 1s further hea ted, 1tcon,cm
1mo a mixture of hydrocarbon s, alcohols, aldeh ydes. and kctones. It 1s on lr whrn the
md1 1’1dua l compounds m rhi s mixture l’apor1 zc and mix w11h armosphcr1c o.~n:rn ib.i r
fi re OCCUii.

Syr, t h et ic Fibers Obta in ed from Ce llulos e
Synthetic fibers ma r be der1\·cd from the chem ica l rrcam1cm of cellulo se. For cx amplt,
cd lulose ;1 ceu1c 1s the fiber produced when wood cellulose 1s reacted wuh acct!C ;ic,d or
accu c anh)·dndc. In co mmerce, the fiber is called acr rut e “1)’011 . Although 11 hd1i a pro-
nounccd strengUl, accta1e ra r on can bc ignmd with a hot1ron anddestrorcdb t•SOITJI’
dry·clc;1mng sohem s. G11’en rhesc- ad 1· crsc features, accr :m ra)on did not rcram popuYr-
ity as J fa bric of choice , bu1 n 1s still used tod.1 r m moflon -p1e1ure film, a1rplJnc -..m~
a nd safcry gla,scs .

,\n01her srmhem product dcm ·ed from cellul ose 1s cellulose XJ nthJtc, ,om mor.ly
, J !kd rayo n. The producuon of rayo n involl’e s reacting highl r purified wood r ~lp
11nh sodium hr dro x1de, followed by che1m ca l 1rea1mem with carbon d1sul f1dc. The

624 Cha pt er 14 Chemistry of Some Polymer ic Materials

0 \
~o

\ 0 I , p
( Cl/ Cll ~ C (JI l ,c-; ; :-.11 I’\1 1 :-.. 11 .,11

II E 14 6 In IM ‘>Cg”‘e”t o f the l’r’.Klo,..o’~ ~ dr ltr\lct~’t of woc1 K. y •”d z ,tp,t’>Cnt ,-,Qlecu ‘es ot
,c,dt compound\ ti-at ha·,e !ht lo,,o-, , ~g Chfm,u1 formu~

11 ‘ “‘ llO ac ,d1 are common ‘y fou nd ,n r\,l t11 ral)’ ocrurior,9 prott;fll The 1nwtsted ru oer may con1ult ~}e j(j ,anced cnrm WY te,tooo~s for ad d ~onal 111formuon COl’lCet1t ng pro:t,n1

rt5 ulting sohmon 1s extruded through a spinne ret. a metal disk havmg numerous
unt hole s, and then mto an acid soluuon th.it regeneures the cellulose a s tm r
nanspJren1f1bers .

Nitroc1lluloH, Nltroutlulose
non1~plo1lv1 lnon1xploslv1

g1d1 gr1d1I

Ano1her example of a S)’mhctJC product dcrm:d from cellulose 1s n11rocellulosc .
This suh>tancc is ma nufae1u red by reacting cellulose wuh mmc acid . Although
h,gh l)’ nitra ted cellu lose- 11 3 chemical c-xploSLl’c, 1he le.scr grad~ of mrratcd cellu –
lo>l’ arc d1ssoked m a sokem and applied to doth ro produce the fabric known as
p,itrn t leather. r rod ucts produced from 1h rs amfrc1a l leather arc strong .Jnd flexible.
l ht)’ include \Chicl e- sca t COl’t’ rs a nd com·erub le tops. Nitrocellulose 1s .Jlso used as
J film-producmg age nt in lacquers, prmung mh, and cn;1mcl nail polishes. The
ni crocdlulose forme rl y used to make fil m, called nitrate film, was highl y flammable.
A mip burned .J t 3 ra te 1hree times faster than an 1dcm1c.illr med piece of p.ipcr.

14.5-B WOOL ANO SILK
Tor mo>t co mmon ammal fabrics cmplorcd m tex tiles arc woo l an d sllk. Woo l 1s the
C’Jrl1• hlir of shee p, goa ts, a nd lb mJ> . Under a rmcroscopc, wool fibers resemble 1111)’,
o1r;IJpping scales , much li ke 1hosc of fish . These fibers bend and co nform to a varie ty of
ph)sica! sha pes. They also possess resd1enC)’ and tend 10 hold thm shape.

Silk is rhe soft, shmr fiber produced br silkworms 10 form their cocoons. Silk fibers are
•CCJ’ mong, ebmc, and smoot h. Under a m1c roscopc, silk fibers appc-ar scm1transparen1,
” h1c haccountsforthc1rlus1rouss hC’C’n . Silk1srcstl1cnr:11sfibcrsrcad1lyspnngback rothc1r
oogmJI position when stretched or folded . These qu.1lmcs ha,·c m,1dc s1!k one of the mos t
11.lt ful fibers for che rcx 11 lc market . Unwmding the long, dchcatc silk threads of 3 cocoon IS
l 1c

Like all 01hcr forms of anunal ha ir, wool and silk arc composed of prorems. 1, h1 ch :Ht”
b1o log1c.1l subs1 J n,es whose mo lecules ha\e rccurnng ammo groups. The cond ensed for-
111u lJs of wool and silk arc C4! 11 w :\’1!! 0 11 and C1; 11!1~ 10 .. , rcspccn1,d y. A pomon of
1ht mJcromokcular structu re of wool 1s shown 1n Figure 14 .6.

Silk conmts of a mixtu re of two rcbmel)’ simple protem s callcJ s,lk f,brom and strt•
l m. The mJcromolccu l,u s1rue1urc of s1!k fibrom re sembles th e stn1 cture of wool m whi ch
X, Y, Jnd Z a re 1nvJri.1bl r – Cl Ii. 110-C~ll4 -Cl 1,-, or 110 -Cl 11 . Sencm h.H J s1m1-
IJr 111Jcrumolccula r strucrurc, bur rhc prmur r rcrnmng grm1p m the pro1c111 1s the
follo\\mg:

HO – Cl l , – CH –
– I

‘\11 :

&cJu ,;c wool and silk arc prote111s, both ha1e , um!Jr pro pcmcs. Ea ch h.1~ a n •gmuun
trmprr;uure 111 t”)(Cess o f 3ppro x1mJtel)’ 1058 °F (570′(); henc e. 11001 and silk uc difficult

Q((urr lngf,ber
obta ined from th e
coatsofshup, llam,s,
go,ts, and se~era l
01heran lmal s
1/lk A natura ll y
occumngprote,np10-
duccdbytheact,onof
s,lkwo,m1

Chapter 14 Ch emimy of Some Polymeric Materials 625

II

I I
U,_’.__

11,nylpol)’ll’H!r • A ny
po~merprodu

Vinytiden•
chloride

to ign,t e ;inJ “hen igmted, buro ,er)’ slo wl )’, \’\;’. hen 11ghtly WOH’ n as m rugs, \\oolcn IC’l
t,k s tc:rid to ~mo l.kr an d char when burn~ng . 1 hey absorb i;u.•ac quam111e~ of \\JfC’r, th~
pt’rm,mng 1hc1r firn 10 be e,1s1l ) extmgu1sheJ .

0
BccaUS,C’ the m,1cromulecuks of Jn11n:il f,bcrs conram bond mg groups ~uch as – C

– ‘,II- , and – ,’,, – ;)- , the presence of ammoma, hydroi;c:n cyamde, and sulfu r di oxi~l{;t
fire SCt’nes 1mohmg {c xt1les 1s poss1bk.

14.6 VINYL POLYMERS
As not ed m Section \l.3- B, the vm)·I group of arnms 1s CI t~=C I t- . For our pur J)OSc$, a
s ubstance: comammg tht”, 1nyl group 1s a vm rl compo~n d . Examples of \’lll)’I compounds
arc: l1s1ed m Table 14. l under 1hc: ht’;i dmi; ~~tonomt”r. A pol y n1t”r produced by th e add, .
11011 polrmenz;mon of ont” or more \”inyl compounds 1s c-a llc:d a vlnyl polymer.

The following t”qu.u1ons tlluscr:HC: che produc11on of St”Vtral commercially 1mpon1nc
\tn)I pol ymers from the,r respc:cme l’myl compounds:

H H

C \Ctl
H H

H H

C C(!:l

H Clh

II H

c =. c i111

H

Cl

11 0 l

H 1-1+/i H+ l1I 1/
.w (” C C C C – C -“‘VII )

I I I I
Cll 1 1-1 Clh ” H Clh

1111 + 1111
1

1111 I I I
.wC- C C \ ………_ C – C -“”‘(1\

I •
11 C l H U .J” H Cl

Pc,1)1110,l , hl,-,,J~>

i~-~~-J . .,,
_ H ~-<.. c;,-,l,"

Uh 0

,\ 1•1nyl pol) mer ma y also be product”d from mulnple l’my l compo unds. For c:tamplc,
che I myl chloridc-vmylidt”ne ch lori dt” capo!) mer is pro duced from 1· 111) 1 ch lonJc and
Vtn)·l1dene chloride. Vmy l chloride and vmyltdent” chlori de art” srnun)mS fo r chlo rocthcnc
and l.l -d1Chloroetht”ne, rt”spt”c t1velr.

H Cl

f= Ct~l –
1l ll

H 71
c -\(in

II C l

1-1 H Cl H
I I I c – c (. (
I I I

Cl ll Cl fl
\1 n,!,h),r,,k\”l)l•h1,

<11\,,,,J,•,.,I" I}"~· • 626 Chapter 14 Chemistry of Some Polymeric Materials

,nerciJll )’, ch c: vmy\ ch londc–l’m yhdcne chlo n dt” copol)mC’r ,s known :i~ Sam11, or
C0

1
: 1, , 1n)hdt”nc: dichlonde ) . .\1an ufocturers form ,t ,mo sh«1s, tu~. rods, fi t-ers. a nJ

~hrr molded ,ccm s. h s fibers arc: used 10 produce a numlX’r of lt”xules, mdud1ng c;upelS,
,urt Jins, :ind uphol sct”T)’ fabrics .

14_6-A POLYETHY LEN E
flh)kn c ,s prepJred m 1he petrochtm1cal indu stry, pnm,ml r b} aadang e1hanc: and pro-

~J1~:i /:~;;u•;a~1:1};~~~~~~; :~et~:s~~!~~ ~~t”~~{r~1~:~:1:n°:)~~1:~·:::,::~1~: t: v:1~~;
rcp

Pol)·t”th)lenr ,s cricounteri:d pnm.ml r 111 two fomlS: low-dens11)’ (c~-1.inkcd) (LOP E) and
high.;.ln1>1t)•( lmc:,tr ) (I-IDPE). A thmi form, low-molecubr-we1gh1 polrc:1hylen<', 1s umqudy used ~, ro,1ungs Jnd Pol •~~cs. Both U>PE and HOPE are wlme soli ds. LOPE 1s a therrnoscmng poly –
fflC’~

11
herl’.3S !-\OPE 1s a 1hermoplasoc polymer. The d.iffc:reoce be,:-.1 t”C’n 1hc drns,ucs of 1hc: two

r:ili•rners 1s anamed by dmr methods of producnon: U>PE and HO PE a re produced by polym-
mzing cth)·knc: m the prcsc:nce of an orpruc Pt”roxide and a Zic-gler-N:uta caulys1, respecmd y.
7ne dens,ry of LDPE nuy be as low as 0.9 15 g/mL, and of HOPE a.~ high as 0.965 gi’mL

Low-dens11y po lye thylene 1s usc:d bri;dr for makmg baby diapers and molded prod –
ucts r;uch as IO) S- For (‘xamplc: , tht” ~noodles~ tha1 children use: in sw1mmmg pool s a rc
fl\,ll’lllfoctured frorn low -dt”ns,ry polycth)kne . t-l 1gh-d ens1ry pol)cth )•knc 1s used numly

10
rn.mufaClurc filmed produCls and hardy storage co111ai ners. Tht” po l)c:th ylc:nt” films arc

u5(‘d 111 {he bu1ld111g mdu str)’ as vapor and mo1s1ure b:.irncrs and m the agricultura l mdu s·
tr)’ for mulchmg, s ilage co,·e rs, g reenhouse: glazings. pond lmc:r s, and amrna l shd1er s.
lndudcd among the com.1mers are pbsuc milk 1ugs, de1c:rgt”nl and bleach co111amers.
SJnd11ich bags, :ind lmc:rs for tr.ish cans, drums, and otht”r comamt”rs.

Alarm ha s bt”c:n r.11scd by consumers o,·cr tht” usc: of po lyeth ylene fil m IO mJnufaccurc
gJ-1bagc hags , dry -di:-anmg bags, a nd othu containe rs th at could m:1d1·c:rtc:ndy ca use 1hc
suflocauon of mf.mrs and small children 11ho com,icl 1hem. To mm1m1.r:e the num bt”r of
dc-ith s rc-sulnng from contact wi th the: film, the following ,·o luntary s rnt emc:nt is oftc-n
c-ml>oss(‘(I on bJgs m English, Spam\h, an d French :

WARNING
KEEP THIS BAG AWAY FROM BABIES

AND CHILDREN DO NOT USE IN CRIBS,
CARRIAGES, OR PLAYPENS TH E THIN

FILM MAY CUNG TO NOSE AND MOUTH
AND PREVENT BREATHING

Both luw – an d h1 gh -di:-ns11 y pol)eth yk·nt” ma y IX’ reqcl~d . Their reqclmg S) mbols arc-
anowcd tnangks e nclosmg 1he numbers 4 and l, rt”Sl’<.'C lll"d)', Jnd bcnea1h which appear the !titers LOPE :1nd // DP£, as follo" s:

Lt L~
LOPE HOPE

l’rodun s made from both LD PE and I ID l’E burn w ht”n t he:)’ art” c”post”d to fin:· . The
dJtd In Table: \ 4.4 show 1h.11 po l)t thylt”nc ,s d1s1 1nc111t” among burn111i; polyme rs msofar
li II rcl e;1>t’s more heat pe r um{ ma ss th .in Jll)’ other cu 111m t” rctall)’ popubr pol) mc:r. Dur-
ing combu s11un, polrethy lenc: produces tend IO d1sm 1egra tc: into numerous burning, mol –
!tn s.lo bul t”s or l1q 111d poo ls. Bt”Cause 1hc mac romok·c ulc:s of polyc:thy lc-ne arc: composed of
Oil! ) carbon and h)drogen atoms, c,ubon mo11ox 1dc, carbon d1ox1dt”, .1nd wa1c:r vapor art”
prod11,cd as combusuo n products.

Ethylene

Ch•ptcr 14 Ch,m l~try of So me Po lymeric Materials 627

r
l!.et•ctk polyme,
• Any polymer who~
ma-cromol~!e1h1ve
11d@ch.iur,1po1,t,onll’d
onthewme1,deol•
chi1,t1ofu1bonatom1

~yndiot.lttk: po lymer
• Any polymer whos.-
macromo!e-<::uln h-,ve i1lt ern.1telypo5mone-d "deCfliltnlilfong• chi11nofcarbon11oms a l.fctk po lymer • Any polymuwt101, miltrOmole-cu fnh.ive rilndomlypo1,1,onll'd 1,dech1ir,s1long1 ch1,nofurbon,toms

V1nylchJor,d,

14.6 -8 POLYPROPYLENE
Th e cr.id.,rn g o f prop.inc pmdu,(‘S mrth,rnc, eth) knr .. md prop) ll” ne. In the P<'troe~

i:: ~~~;1~:11;.1;~r~~~/;~:1u:;)~::;,~~•1::1::1:~~:n~~r~:,~;;/~J~~:~l”mc,,l(;:
uni t ‘ CH• (“f!..vv. rrpr~hng

CH1
Polyprop)lcnc is used co 111 .111ufacturc con1r11nc1:d p rodu cts ra nging from sdk fbi:

co ng,d conramcrs. Examples are outdoor 1.1bk5 and ch.1irs. sh a u c rpruuf g!J s~s, 3~ 1~ci:;
gr.1;:s and 1urf. p •~s. rOp(S, ne rs, rwuic-s. ca r p<"lS , .ind c'.irpri p.1d d mg. The plJs ric ite m,

;~~;,:r;•~~~-a;~JJ:;;~~,:ta~~/:~:1:po~~fs: ; ~;: lc ne. l hcr mdu d c 1h e dashbo Jrds, by:
Br using a Z,eslcr- :’\’a u J cat.1 ly~t to m,11J te pol)mc n i:at1 o n, 111anuf,1c turc- rs hJ ,·ebttn

ablc ro produce pol yprop) lcne so thJt t ht· branc h mg mc th ) I g ro up 1s ,lrraycd regimenti.U
:!:’!.:~;o~~~:~~~;bon backbone, gn 1ng nsc 10 t he follo win g t h ree t)” pes o f polJ prop/

rsotactlc polymer, 111 1, hK h rh e mcrh ~l gro ups arc- :111 po1 nrmg m the ~ me dm:-mon,
“”‘- CH: – CH-CH: – CH – CH ,- CH – CH2-~H – CH: – Cli – CII: -~H …,,,,_

CH , CH1 CH , C/1, CH, CH,

Syndiotactic polymer. m ” h1ch alt erna 1e mcd1) I grou ps pom1 m oppo ~l tl.’ dir ec:riocu.
CH , C H, C H,

I
“”- CH2- CH CH2- CH -CH:-CI I- CH:-

CH 1 C H, CH 1

Atactic polyme r, m whic h thl’ me1hy l gro ups J rr rJn d o ml r o ri e nted :
C!h C H,

vv… (“H, – CH -nf , – Cl-I – CH , – CH – CIJ. – CH – CH ,- CH – CH , – CI I “”‘-
– ‘ – – I – I –

Uh CH, Clh CH 1

These md 11 1duJ! po l)”prop) lene ryp< s may be CJ SI m to s hapes . drJwn 11110 sheen, or exuudr-d mro fibe rs, rhus producing a r,1nge o f dl\·emficd p ro du c1s.

Poli propylene 1s a rrc,cbb/c polJme r. T he recrd 111 g S)·mbo l for po lrpro p)·lene 1san
a rrowed m J ng le endosmg the n umbe r 5, ben cJrh which a p pea r th e lett ers rr.

it
PP

Pol)prnprle ne dO<'s nor 1gm tc C-J Sil )'. H O\H1cr, o n <"xpos ure 10 1m c-nsc hcJr , pol)pro- P) kn<" th nmal/y decomposes mto a m ixt ure- of h)d roc:. r bo n vapors. Thi s rmxrnre ca rdics fircJnd burn s.

14.6 -C POLY(V JN YL CHLO RIDE)
l’myl chloride, or chlo r()(‘1henr-. 1s a gJs pnrn:m li m ,rn u focrnrcd by t he c,HJ1)HC dehtdr o-

chlori11:it1on of r ,l -dichlorocd1,1 ne.

628 Ch ,pter 14 Chl’m1st ry of Some Po lymeric MiJteri1ls

II

CH ,- lh.’I .. HCl f,l,’l

(I

\, ,l,t1l”n i.. lhJr, l’~nd’ nlc

111′ th~~~
1c’:~:1

1
~
1
;:;~s:’.~;

1
1: ~~:~e~;/~sa~;~~:~·:i~ ~~:~~~o::; t he a ir aff<.'CI\ 1hc crn t ral nc r-

,ou> ,ptcrn a nd c-an cause d11.~mcss, drows1ncH, and hca dJchcs. The ga s 1s rcgMd l.’d as a
~fl01, 11 hum J n cJ rc1r1ogr n, because hum.in e ~posurc b)” in hala ti on hJ s bee n aff1r ma tn t’ I)
linkrd ,1 uh the onse l uf IL 1er angiosa rco m.1 . The la uncr pc- n od fo r th e onse t o f thi s can –
r

~mrlo)c rs 10 limi t t he ,1ni! c hl o ri de conce mratton 10 1-1hich t’m p loic-es arc expo sed m t hc
,.ork pl Jce ;H I pJrt pe r m il lion, a1e raged 01·er Jn 8 -huu r 1-1 o r l.: dai·-

Pol) (Vlll) I rhlo r1de} is prod uced when 1·m) l chlond c polpnc- n.zes. Ir ,scom mo n lr rccog•
nllcJ Ii)” II >’ ocron )’m , PVC. T he um1 t ha t recurs m 11 s mJr-romo lccul<":S as the fo llo wing:

……,.._ CH ,Cll “”‘–,
Cl

Thr prescuce uf t he chlorine- atom s gi ves PV C wmc um q uc properti es. Fo r exa mple, t he
J,1 tJ 111 Tob ie 14.4 show 1h a1 when PVC burns, lr ss heat 1s emmed per inns co mpa red
,. 11 h o ther comm o n po limc rs that bum.

PVC is the po l)•mer use d 111 man y home-con s1ru ct1on producis like fl oor tilt’s, lig ht mg
h tures, vin yl pand s and s1dmg, co nduits, and w;i. 11 co1cm1g s. Figure 14.7 s ho w s 1hJ1
pVC 1., a lso the pol ymer used to manufacture- pipe and pipe fl mngs . PVC 1s 1he pll suc
,n,ulJt io n sh e:i rh used m 1·1rtua ll r all modern clecm cal wmng. PVC 1s also encount e red m
1m,rJ uo n k a th er, shower c uria ms, uphol stery maten J I, 1″ 1nr l ramcoa!s, p la sti c pac l.::igmg

FIGURE 14. 7 PVC
ph,.mbongp,~oftena”
U~Wlt ti.n Nll\roor”‘S
and~,t~sforr.ot-aM
colc-w,ie,delrveryto
f.t1.”s. 1ocarryd·ain.aQI’
and w ~eandtovenl
000″ Thel’V(p~SU!>u•
allyare,o,ne dtocoo~•
0

Ch11 pter 14 Chem istry of Some Polymeric Materials 629

r

ACl)’lonitrlle

m,ueri.il~. g.nJen h,J;e~. Jn J mrd1,.1I rr0Juc1s i\ppro ‘\1 111J1el ) 70 °~ of the pol) j
chloridd pro,lu,rJ l1I the Unm·J \ tJl<'"S " u~ed Ill bu~ld111i: c~~~1 ru , 1m11 mJttn~I~. ~ 11 cor,.,l)nlt'ri .ue Jl,o commcr.:1.111) J,.1,l.1hk m pwJuct, ~ud1 ,h hims, f1~rs. sheet,na ( mo!Jmg~ . llle1r mr,h,1rnc,1I prupr m t, ,,H}' !rum ri gid to clJ~lumi.-ri ,·. S, Jn,j

btn~~~C,: ~~~);~,~~1″$1:~:~~~:~nt.’)·lllNll 1;; ,111 Jrrm1eJ 1r1.111 gle t·ncloi1ng the nuin~, J,

Lt
V

l’\’ C 1,; high!) ,u,;,cep11bk tu degr.1dn1on. 11 h1ch results m u11~1ghtl)’ d1 ~o!o nng a
lo~~ of rnrch.1111cJl propn11r s. For tXJmpk, 1hr 1111)1 upholm:-ry 111 an au romob,le 15 /’il
uJII ) soft Jnd sup ple, but II b«omes hrndc aud cr.Kk s JS the .w10111ob1le ages . As ,, ru.
pJ>~t·•• the plJ st1c1ur ,3ponies . . ind tht” upho lstn)’ t,ike~ 011 a n t’ nt 1rd) ney, chJrJCt(tltlt

Althoui;h P\’C dOC”i not eas1I) 1gt11tt, the ,; amt 1s not true of th<." pb~t1 c11ers added to PVC product >. l he plJst1c1zer most common!) Jdd eJ to PVC product s 1s d1 (2•eth) lhe I
ph1ha lJtt iDEIIP ). The eJsc 11uh ” h,ch PVC products 1snur mcreJ srs as 111ore and ~
plast1C”1ur ,s 1r1corporJtrd mto them .

At devateJ temperatures, PVC thermall y d…-composes and its dceo rnpos1 11on prod llru
burn. G1\tn 1hr abunJJnct of PVC products th at firefight…-rs ~re li kel y to encounie d
mg a normal fire, the- d…-composmon of pol) (lm~I chloride! ma)” co11srn111e a pol:nt:
heJlthconcern for the fol!oy,mgr…-a!-OnS:

H)drogen chloridr 1s produced when PVC burns. H)droi;en chloride-~ the h,11 .
ard of inhalation 1oxJC11y.
Pol)chlonnated d1beniofurans anJ d1bc11:w·P•d1oxms are produced durmg che lfl«>ln-
ple!t combu,non of pol y(im)I chloride ). Exposure to mmu tely low d1oxm concemr3.
nons cau>tS a 1.1r1cty of 1Jlm:sscs 111 md111du.,h and th eir offspring.
All PVC products comJLrl some concem uoon of the vmrl chlo ri de monomer, ustully
less th an 10 pJrt S J)(r m1lhon. tha t docs 1101 b…-corne a component of the pol)mer. h ll
prudent to assume thJt wme l”myl chloride monomer 1s rdeased to the en1·1ronmrnt
Y.hencvcr PVC producrs .ire expos…-d to ele1·ated tem J)(rJtu res. Th,s may reprC”$(m l
hcalrh concern, beca use the- monomer 1s a human c:ircmogen.

Some lc1·cl of 11n)I chloride is released from all PVC product s d un ng 11s procmmg
mto fobnca red products. especially “hen th e PV C 1s htattd to a tempe r.mire that cau1e1
11 to melt . To provide emp loyees y,11h an a11ar…-ncss of the presence of 1h1s human camno-
grn, OSHA rrqu1res employers at !9 C. FR . § 1910 . 10 17( 1\\ 4 ! to affix the fol!oY.ingil~
to contamers of 1,mprocessc-d PV C:

14.6-0 POLYACRYLO NITRILE
Ac!) lon unlc 1s J colo rle>s liquid prod11,·rd from prop ) k nc , 111Hllll!ll ,1. and o,1grn

lr1 s J101Julc-,toi.1 c.Jn d nJrn111Jblehqu1d.

ll!, =e C. 11cl
– ‘

”
630 Chiip ltr 14 Chem1my of Some Polymer ic Materia ls

p,,IJJcri lon1mle re)ult) i,h en acri lo 111t11le 1s polJ mer i,ed. The um t th,H recurs 1n 11s
!flJC1′-‘rnokculcs 1s th e follo 11mg·

Cll ,CH

l ,\

TM s)llthe11c Pol) llll’r 11 ·1′ the fi~ t to become conunercull y popubr m th~· forn1 of ao1l,r
(,b rr>, J trm1 refcrnng to those- fibers corn~ of .11 lc-a s1 85% by ma~ of Jcr)”lon11rtle unifs.
lodJ).aCl””)licfibC”r.a reu scd prnnJnl y111c-Jrpe1sJndother1ext1les,hcc;-i uSl””they :ireres1stJnt

sunhi;h t, qluck ·

i\t fire scenes, hydroge n cy anide 1s productd Y.hen ma 1cnals made of pol)aC.r)lom ·
trik undergo therm.ii dc-compos1t1on. l1fe-1hrtJ tc111ng concentnt1ons of h)drogcn cya ·
“idf(O t1ld begt11 t r,11ed._Wheth cr th1’i1sa s1gn1f1 cl nt focror mcJu\ingthc de;ithsof
firefi ghte rs l’ii 1111known. 1’onctheless, U 1s prudent to as~ume thJt exPosure ro 1h1s toxi c
gJsocc ur rcd.especully while fighungrc<;1Jennalfircs .

14.6-E POLV (M ET HYL METHACRVLATE)
\[cth)l mcth .1cryl.He 1> l colorless liquid th.it 1s manufacture d from acctont, hydroi;en
q Jnidc. su lfuric acid, and methlnol. h IS 1ery 1olJulc and h1ghl1· OammJblc.

Se1erJI po!p1nyl polym ers are produce d from the este rs of acr)l1c acid and meth ·
JC!Jhc :1c1d. An exampk i> the commem.1lly popubr pol y(mcth)I methacr)late ). whic h 1s
frequenrli· des1gna1ed as PM MA . This pol yme r 1s produc<'d by polymem.1ng me1hrl meth· Jct)btt. The repeatmg um t m P.vtMA is the follo\\1ng :

Clh
= CH:-C =

f=O
CH ,

PM,\\,\ 1s a compone nt of the pb;uc products known co mmerc.ull)’ as PleXJg]Js and
Lucn e. It 1s as dc,1r a; glass but can be manufucturc-d as a tr:msp.irem, 1r:1nsluc<'nl, or opJql,e mJtenJl. Because P.\1.\lA IS l"lrtUJ !l )' unb~abble under normal con d111ons of mes~ and ten · >1o n, 1t 1s usdul m wmdsh1dds. wmdows, and ot~r prod1K1s s1multanoouslr requmng WC’ather
rC’S1SIJt1Ct, Mre ng1h, :md fr.tnsparency. The l.if6tSt use- of P.\IMA 1s a1SOOa tcd wuh the nunu ·
fo ctun- of d1spl.i ys and ad, emsmg signs. hut the pol)·mtr 1s al,o uS<'d to mJl.:e l,i;htmg fixt ures. bo1ld,ng pJnel,;, and plumbmg and b.uhroom fi ~rures. The nu!itary uses P.\i.\-lA m cockp11 e3nop1cs, w111do1, s, gun lur~I>-, and bomb,m:l1tr enclosures. It IS a lo;:o used as a compuntlll of
b te~ and enamel pJmlS. a di) 1ng 01[ for 1am1shcs, and J fimshmg compound on leather.

14.G·F POLYACRYLAM ID E
Pol}JCrJIJ rmdr 1s a WJ!CMOlubk pol)mer produced by the pol)mmzauon o f th e mono •
mcr.1CrJIJn11dc,Js follow s:

c 11 , Cl! Cw,11

‘ \.II,
– Cll,- CH -1
I . <; ojiq l Nil e 111

h 1s used pmn.ir1l)· d11nng paper 111J nl.lf.1ciu n 11g and WJ ter-1rca1mem proctsscs to coagu •
IJtc the >1i-1prndcd so lid s 111 11Jtt’f. It is :il.o us.ed ,1s a componcut of u ,e.1b111 or grou t u~cd

M.ih yl
methecrylall

Acryla mld e

Ch.1pttr 14 Chem istry of Some Polymer, c M.Jter,ah 631

II

tpoxy-in • Ariy
po1ym t r producfd by
lhfcond~tJonof~
d lol ind ~n tpo l •d~

:~;:~J~;1~:~k31~J ~~\:~-h~na:~~.:~1~l:Ag;;~t::n~ :~}:~11~:~1;:~~:;~~rcti diS!rib~1~
11nhdrc:w 1hc proposa l and mstr;1d urged 1ht adopnun of m.1n,1gcme111 p;Jct::::~t. l:,,1,
the po1c-nu.1l nsks ca u)td by cKposurc m acr) IJ1111dc. 4b.i:,:

Polracr)!Jm1dc 1s nomo:,,1c, but chert are hcJlth concerns J Ssoc 1.11ed wnh ex
11 s monomer. Acl’}IJrruJe is bo1h a neuroroxm and a prob.1blc ca mnogcn . \X’orf:: Ullto
sure· mar occu r m.1d1crtend )’ b«ausc rcs1du;1J acr~l.irrndc rcm.ims 1n the pol)mc r riq,o.

I lra hh concern s rd.u rd 10 acr) l.imidc cxposurt haH c1cn i>(rn ra1~cd by n~t
l)IS, because the sul,,1ancc forms at [O\\ co nct ntr.mons dunng 1h r h1gh -trml)frat11r~I~
1ng, roJsu~g, a nd b.1kmg of foods m.1dc from plants, tspcc 1all y Frrnc h fries and “1′
chips . FDA s posmon 1s 1h:u the :icr)lamidc conccmration 1n fned foods does not JlOl.1. ro
hc-alth mk fo r most people. 1

c-xpo:;d
1
\:t~~ae/~~;h1tnh: fir~ne~i::~~;~;~:.’,:c-~;~~~1:~c-r~:fi~~t~~~ -\\hen PM.\U u

14. 7 EPOXY RESINS
ln Sc-cuon 13.l •iS, we- noted thJt Bisph enol -,\ 1s used 1n th e- pol)mc- r 1ndus1ry10 mJ f
nu,: epoxy resi ns . These are thermosetting pol)mers produ c-cd b>· the condcns.1ho~u07;
dml and .in epox1dc. For tx ampk, B1 sphenol -A and ep1chlomh)dnn react as follows:

– HC!ufl

Wh en the res m IS noss -lmk ed, th e- rcsulung pol )’mrrs arc- c- sp,:c 1:1II )· hJrd, chem1(;11l f
resistant, .ind nonco rros ive . Ther arc- th e strong,:s t adhe\ 11 c-s kn own.

Epox)’ resms ar<' ustd mm.in )' commt rci.11 applicauo ns, mcludmg prottcllH coannp fo r spons c-q uipmt nt, the hulls of ships, met;il eontame rs, and km:hen Jpphances .

14.8 FORMALDEHYDE-DERIVED POLYM ERS
T here are severa l formaldehyde-dc-m·ed po! r mcr s ustd cornrnc- rciallr. All arc 1hnrnovt·
tms polrmrrs, and all arc productd br condC”nsJuon polrmenzJt1 on . Th<" follovo111g thrtt are noted bndl y:

Plm,ol-fonnaldth)’dt. This was thc- fi rst fo rmaldch)d c–dr r1.-cd pol)mer 10 t-..:dit-
co1 ered. Ir IS best known br tht trJdcnurk B.1k c- li1 e, .ind has bun mc-d m molded rl«
meal caH’s, .idhcm ts , l.t mmJt ts, and varni she s. The molcn1l.1r scructurc of us rrpurmg
umt 1s pro\lded m Table 14.2.

Uua-foni,a/dtl,ydt. As nottd m S«non I J .5-,\, tht· nuior use of urca •form;il.k-
hjdc l~ as the bmdtr 111 p.m1dC” boJ rd . The rnolecub r sir uc turl.’ of u s npc.111ni: uni! Jl..o
1s prov,dc-d m T,1 blc 14.2.

632 Cha pl t r 14 Chtmrs try of Some Po lymer ic Mattr1als

• ,\lela1mn e- formaltlt!,y,I … Thi s pol)me r 1s U!;Cd to produce the hard c-s 1 pl.imc items

10
,oniimrcc : l,inunaied coun tcn ops like Form1 C’J; l.1111m.1i ed flooring; k,ichcn cJb1nc1 s;

J.,iornou1c wpcoJt s; finishc~ for appl1.1nccs and mewl furmturc: molded pl,1s1 1C t.ib lc ·
-,,.1 rc Jnd \..1tch t n uten sil s; and food conca111crs . The mo!«u!Jr stru ct ure: of 11 s reJ)(‘aung
uni cis the follov.mg:

“””””‘”l””‘” CH~- ‘\ ll -C~ _,c- /\H -C Jl !””‘I~…………,.,
N

14,9 POLYURETHANE
A uffthiln e, or Cilrb;i mate, 1s an org.1mc compound producc-d by the: c.italrzc-d rc-act,on
t-(f”Ce n an alcohol and an org.imc 1~yanate. The chcm1C31 furmu l.1 of a ~,mplt organic
i1ocy;i nate 1s R- 1’= 0=0. The prodocuon of a urethan e rrur bc- ,llustratcd by 1hc- fol!ow-
,ngcquJuon, whtrc Ran d R’ arc- arbitrary alk r l or aryl groups :

R – N=C -= 0(1 1 R’Otl (I) R- NH-C(rl
I
0- R’

A polyurethan e 1s a po!)mcr producc-d b)· rtaClmg a glrcol and an orgamc dusocp –
nltf . Organic d11SOC)’Jt1,lte molcculf’i hair t110 IS

o- c= :– –iAi N = C= 0 1[) -+ HO – Cil: CH :-OHr/1

V,L etii

The hc.11 rekJl.(:d durmg 1hr pol) mu1z.i11011 rcJct1on cauH’ ~ 1h e blo,11ng ag,·m to 1Jpor-
11e Buhbles of vapor su bscql>enll ) J re C3ptured \\Uh1n the ,1scous liqu, J JS 11 pol )men , c\
Jn d e.:p.ind ‘i . ,\ pol} url’thJ11c- foJm resulr, 11hen the froth) mi xture sol 1d1fics .

Sc,e r.1 1 commcrc iJ ll}” a-.ulJblc pol) mcr s are co mpo\e d of mJcromolc-niks 111 which
the- fu ll m1111g grou p ol .uoms 1’i reptJted 3lo ng tlm r molec ulJr ch ,1,ns:

0

o\ !l

ur1tth &n1t{(.trb• m;1 1t )
• Anyorg.tn ,ccom •
pound h•~”‘!I thf g,n-
tr•! chem ,c.al formula

0
R- NH – C

Isocyanate • An
org•n,c<0mpound who-;fgfn1tr.Jlch,m.c~I lor mul i ,1 R- N:=C~ O

po!yurethan,i • Any
pofym,rproducedby
the cond,n~t,ooofa
glycota nd,norg an,c
d»1ocy,n,te

polyamlde • Any
oo lymfr

fhe ;.e .ire c.i lleJ poly ami des. N)lo n 6,6 and the pol)urcthJnes are e.:.impks of polj•annde s.
Chiipler 14 Che mlnry of Som, Poly mer ic Matc-ri ;,ls 633

14.9-A COMMERCI A L USES OF THE PO LYURETHANE S
Emergency re\ponJcr. .He usuJll) f.wuliJr “nh JI le,.IS.t one u~c of po l) urc thJn c, 10 It
porJnl)’ sul storm ;ind sn1rr dr.11ns. The pol)·uret h.mc products t ha t are a\JiiJblec n,.
mcrc1Jll) for 1h1 ~ purpose arc c11htr shee rs or sca lJnts thJt can pro\·1dc J bar~r r :
entrance grate). l lw )hct!S arc s,rnpl) lJ1d 01er the gra tes, ” hcrt.:a s the foarn I\ di sthJ ”
undrr pressure from a qh nder ,mo , he grates and allo\\c J co harden . Both prod ri;:rJ
1rnt contJmmJteJ wJtcr run-off and sp,lh .111d leJks of liquid haz.udous ni a\er,:strt-
cnrermg the drnmJge >)• te111> . on,

Far more commonly. pol) ure1h.111e foann arc l’llCOlltllered JS ngid or flexible pl~st _
th :11 hJ1e been manufactured w11h a wide rJnge of add1t11e > like s ta biliurs, d trs. (:;
~:~’\ri::~j:,:~~u;~~~::/he ngid Jnd llcxiblc l)’pes of pol)’urcthanc mused pnm~rJ;

The rigid foJm 1s prtmJnly used as U1\U IJt 1on, soun d -dcJden 111 g boJrds, and waU

~~a~~~~J~::;i~i,1:t~1~;n~ :;:~~~•:~~~:t:~~dd:/~;.,~;:~~; ::sc:1:~r~n~~:
msulatccx1:erna lfud1ank sonspJceshu11lcs.
The llex1ble pol)’urethane foams arc used m carpel paddmg a nd beddmg, pillow’!’
fu rn aure, shoe soles, medical splmts, and a utomobile-st a t cush1omng. ]n these fo~
products, the softne~s and resiliency of polyurcth Jn e IS the dcstr3bl e feature .

•i·l§Hf:iHfilifl
Wh.ctl~916e!~pinolPQ’)’l>’tthll’lt)IOi,tt5 srre1~,1

Solu1Jon , P~,,_,fftr·- rr;i,c:rorr>Qlf.'(\.llt1 “•”‘ n;.,r>drtds Of tNius1nds of ;, u n 111,ui me foik,;,, ‘lg

Bl!U~i.t 111•” ‘I •n .,.,…d.llX, of~ llogtn atO’l’11 ,n tl-e 1,n,t, Im pOlyl,rethane J..ckeu 1moldfr. 1ht lOl!IC
~1productdllftn)’drogtflcyanOl’.Urbonl”Ql’IOJ<.Of'ntnc:o, .'otilndMrogtn C,o.,dt

14.9-8 POLYU RE TH ANE AND FIREFIG HTI NG
AU polyurethane products burn II hen exposed to suff1c1enr heat. T he produc ts made fro m
che foam bu rn eas1!y and r:r.p,dly. The rnc-chamsm of pol)·uret hane fires begms Y.Ub the
thermal decomposmon of the pol ymer. which products compounds 111cludmg btnww,
rolurne,acetaldeh)’de, :icctonc,propJne.alkenes,and h)’drogencyamde,allof 11 hich
readil)’ 1gm1c upon exposure tu an 1gmt1on source. The format ion o f hydrogen qa111dc
durmg polyurethan e fucs tllJ)° pose :in mha!J.uon haza rd . One pol)’urerh ane combusuoo
stu d)’ showed rhat 1hc rnaxunum ) ,e ld of h)d rogen C)’anide per gram of polp1mh~ne
fo Jm ranged from 0.37 to 0.93 milligrams unde r nonflanimg co nd11ioM Jnd from O.S to
1.01 m11l1gram; under llammg combusno n. 1

PolrurclhJnc fires mJy be cx11ngu1shcd cffrmvd)· w ith rh c application of wam, bul
because: the burnmg product s reram cons 1d erJb le hc,11, 11 is essential to check for tou l fire
cx1mgu1shmenr to pre,ent their re1gnmon .

~,;}:~:”‘T::;,_i \~1/;·~ ;:;:~ ;ir~..:;t•mllljl ,p,x,n ,n ,ti, ofig.,, from 2 °’I ,h.ik m 0<1 •'ljl; rro.."""' 6~ Ch •pter 14 Chem istry of Some Polyme ric Material'!'

It hJ ‘i been well acknowledged t h.u C,luhon mu~f be txcrci<.ed "hen fightmg foes ,n ,vhing polyurtthJne products due to the putermJI for ,nhJlmg mtrogcn d1ox1de. Prod1 - sious qu.1nt111es of this gas arc produced dunng pol)urcth.ine fires . Its presence poses :i n ,rc reJscJ nsk of mhalJt1on toxicity tu bu1ldu1g occupJlll\ and f,rdighters . This nsk 1s , 0 n,, Jen·d so grea t tha t s.1fel)' engmeers rt'Conuncrid the use of a warnmg label such ,J S

;he fo[1o1

The smoldering Jnd open -!lJme 1g nmo n of co11>urncr products eontJmlflg polyurc –
ihlne fo3n11s a prtmJr y cause of deJth by fi re \\lfhm the ho me . In parocubr, the polyure·
th~nc foJm m upholstered furmtur e constitute~ a srnous fin· haurd. In 111 st 4 mmutes. a
iofJ fire lllJ )’ engulf a h\-ing room m flames and produce smoke 3nd toxic &31-tS, In tl11s
short ome, the ternperJture of the surroundings ma)· ele1Jte to a staggerin g 14QQ• F
1760″(). Pol )Urt:·1h anc foam d1~1r1buwngcnerJll)’ pro,1de >1Jrnmg nonces Mm 11ar 10 thl’
fo llow111i;roupholste red furm(U r<:mJnufaccurers.

All Polyurethane Fo am Can Bumi
In case of fir e, ser,ous 1n1ury 0 1 d e.ith un r~u1t from extr eme
heat, rapid o.ygen d epl et ion. and !ht production of 10,uc: g asM
When ign ited, polyurethane fo.m. l

To reduce their potent1,1 I for 1gm11on, t he pol)ure thJ ne products encountered 111 the
wmempo rary mJrke t ha,c ~n formubced wnh fire rcurdJnn like 1h c pol)’bromm,nrd
J1 phen}l et her~ (St’<"llon 13.4-0 ) :md chlonnated orgJnophosphJtes , or otherwi se treated 10 reduce the ir cJse of co mbu suon. CPSC has expressed c.pcc,;il conce rn about the use of trls{\,3 -d1chloro1soprop)I) phosphJIC, or TO C PI', as a plas11c,1cr and fire retardant 111 fwm pJddmt; and 01her pol)'urethane products 10 which infant!> and toddlers often arc
uposed. l nf.i m s and toddl ers arc csp«ully 1ulnerable 10 TDCPI’ cxpomrc because thcr
s~nd s1gmficJn t 11me m con1.1c1 w,rh the uea red foam m mJmesses, car seats, and p1l-
lo’II>. hposurc 10 TDCPP ,~ considered :i health rLSk bccau~ srud1cs hnk exposure with
1hr de1clopmcnt of cancer. In rl’sponse to thi s potc nml heJ\ rh concun, New York prohib –
ited the >J!c of products co111J111mg TDC PP intended for use by mfJnrs and toddlers Jft<'r De.-:cmber 1, 10 13.1

·t,,._., Hu.i ,J A’-‘<'>.\.!Tlffl t l\i “”t,• [i,Jr,, ,;t 0 ,, rl,, tJm•oJ• • •••’Y of t n,,/ J J,cl,/ut<>Uu/1’0S,)I 1,l,01~ /,Jtt !,
C~~lorn1.1 [n, ,ronmo nr~I r rotc-cnon Agcno- \10 111

To1r, Uuorool hyl 1n•
(foo l

Chapttr U Chemistry o f So me Po lymer,c Mate ri als 63S

I

r

Tetrefluoroethvl•n•
(nonfl,. )

TDCPP hJ, rh;,- followmg molt·cu!.u ,iruc ture:

0
1ClC H, 1:- CII-O – P O – C H -1 C lt ,C’t >2

0
llCll : – C H – Cll1Cl

,, I I l)1c~ l””””-‘rto-P}I/ rh<»r h..11 . ,rDCl'P f

h s acaptJb te dJil)’ 1m.1k<" concc-mr:mon wa s cst,1bl1 s hd br C J>SC a~ 0.005 mg/It
body \\Ctght. Yet, polyu rl” lh :rnc products ofien contJm TDCP P at concc- ntr.itio n;
t -. ceed th1svaluc: .

14.10 HEAT• AND FIRE-RESISTANT POLYMERS
R~arc h chem ,st.s h.i vt” dc:vo red consi derab le time to lea rning how 10 produce and nunu-
factur,:, polrmcrs that a rc heat and firc- res1sl3nt . Their re searc h efforts ha\e re sulted 111 the

~~~~:~7•p~l;:·;;:la~:n~.~;;,1cd~~:~~:sf~~1~0:~:~a~ouus~h: ~a~;;,;i~.1~~;:~ ~t:~~~!!:~
products , espc-c1ally building cons1rnct1on mJ.tenah an d products for home use.

14.10-A POLY(TETRAFLUOROETHYLENE)
Tetrafluo roc:1hylc ne IS 3 gu produced from c hloroform ,m d h ydro fl uo ric acid . It 1s u~

10
m.rnufacture poly (rcu.ifluoroc:thy lenc ) (PTFE ), whose cornm e rc1,1I name is Tr{lo>i . Th(
n·curnng umt 1n us rnacromolrcules 1s ,,vv- C F2 – C F2 ,,vv- –

Teflon rs well known .is the polymer used to produce no11Sf1ck coo kware. h al so 11
used to produce 11 1rtuJlly in dc s tru cnblc iubmg. g:iskets, 11a l11cs, .ind cable msula11on.
C hcm1.rs often use Teflon tubmg m bhoratorics • .ind card1olog1s1s use it as amfic1JI Hins
Jnd anene,s . It is .ilso used in p.1ccn1.1k c: rs, dentures, and man)’ othe r manufactured prod-
ucts . Teflon 1s also th e: polymer used 111 the waterproof fabric ca lled GORE -TEX, v.hKh
1s used to mJnufacture thc spo rt swear worn by campers, sk iers , an d golfrrs.

Teflon 1s extr:iord manlt• heat resiotam. Tefl on prod uct s perform well when expoW
10 te mpera tures rangrng from – 400 to 482°F ( – 240 to 2 50″C). Nonmck cookwarccomd
wnh Teflon can be he.ited ro tempt”ratures m excess of 932°F (500°C ) w11hou1 burning.
Teflon IS a lso ext raordinarily un re;a c m c when expose d to hot corros11·e ;acid s. For th11
rea son .. Teflon IS coa1ed on 1he 1nterm r wall s o f ta nks intended for s tor mi; aods.

14.10-8 NOMEX
Nom c x 15 the traden::1mt”of a pol)armdc produccd by t.hc co nd cnsauon of 111 -d1.1rn 111ob(n
zenc- and 1sophr hal oyl chlondc .is fol lows:

From the fibers of 1lus polymcr, a heat · T(“SISt,mt fulmc 1s produced. Erne ri;ency respunders :an:
fom1li:i r wnh thts bhnc bec:iusc 11 often 1s used 111 th e urnforms worn by fi rrfighrcrsand rJcec.lf
dn \c rs. The fot-r1c prO\tdcs an ex1r.i element of thermal protection to it s users.. l)(‘(:JuS(” S’onit-”
carbonucs an d thJCk c ns when expuSC’d to inten se heat . This mc re:ises th e protrcm·e bJrua
bcnilLTn the hc:it source and th e skm, thus mmmm.111g 1he JXl tenu ,il fo r burn m1ur 1es.

636 Chapter 14 Chem,stry of Some Polymeric Materi als

14.10.c KEVLAR
Krd J r 1s the commrre1.1I 113111<' of the po ly.umde produced b )· th e condensa11on of rJi .1nunohenn· nc and te rephthJlo)·I ch loride .

t:r,1,n 1s fbmcproof and m:i y be dr.iwn mto f1br rs ha,·mg 3 s trength fl\’e ti m es stronger
thJn s1cel. Gi ven thi s astounding res1li c nq •. fabrics made from Ke vla r fibers a rc u sed as
ihc mnforccmelH 111 bu llct -resis t:im ,·eus and helm ets . A 16.4 – pou nd (7.5 – kg ) vest
lmed with Ke, lar and ceramic plat es CJn stop arm o r-picrcmg bullet s s hol from h1sh –
po,ier rifles. A 4 – po und ( \ .8 -kg ) helmet !med with up to 24 la yers of Ke,·lar 1s appro x –
irn:mlr 40% more res1s rant to shrapnel than th e steel helmet s formerly used by the
mi li1ary. Kevl.ir has also hccn reinfo rced w11h pb st ic rcsms to pro,·id c protection
JgJll’lStmuhiple ha zard s.

No single produc1 compares w11h Ke \’ lat m rcrms of th e number of h,·es saved thro ugh
11 1 USC’ , Thousands of ::1cti11c police officers arc alive 1od:1. y because 1he y won: Knlar , ·ests
Jnd helmet s durmg t he lme of duty.

Aside from 1ts use m m1ht:1.r y and police bod)’ ;armor, Kc\’ lar 1s ;also use d m np –
resis tJlll Jeans. pro1ccu11c glo” es, boots, skis, hockey suc ks. golf ball s. ropes, cab les. boa1
hulls. a 1rcraft -s1ructurnl pJr ts , rc111forccd-suspcns1on – br,dge stru ciure s, and flame –
rrn~t3nt manrc sscs. So me ti re manufacturers now arc u~ ing Kev lar to remforcc th e trea d
of rJd1al automobile ti res and mJkc them rcs1Mant to tor s io n. ten sion , ;and heat . By usmg
Kcvl.ir, ti re manufocturcrs hJ\’C produced off- ro;ad 11r cs t hat arc ne.irl y 1ndcstrucuble
11hcn dri\’en O\’er rou g h te rrain s. Becau se Kc1·br 1s sta bl e at high tcrnper:ilurc-s, it 1~ also
u,cd in so me br:ind s of the protecmc clo1h111 g wo rn b)’ fircfigh1trs .

14.11 RUBBER AND RUBBER PRODUCTS
The 1crrn rubb e r rcfcr s to an )’ of 1he naturJl or synthtuc pol ymers havmg two m:un pr op –
m1n: ddorm:1.t1on undcr siram and el ,1st1c rcco1•ery af1cr \’Uka mzau on (described m Sec –
llOn 14. 10-A ). These rublxrlikc- pol) me rs arc rnlkd elas tomers .

14.11 -A NATURAL RUBBER
N1tural rubber 1s produced from n::1turnl l.it cx. 3 whnc flmd that ex udts fron1 cuts Ill the
bark of the South Ame r1ca11 rubber tree l·lrve.:1 br,JS1l1ens~ – Tht nJtural latex co ns ists of
Jpprox1m.1trly JO% to 35 % by rn:1. ~s of r,s – 1,4-pu ly, so prene. Its gentr.11 chemical formula 1s
I· ·”- CII ~ T C H – CII !”””” ),. 11hc rc 111 s a l.ir ge mtcgrr. \\;’ hen geomc1nc,11 isomerism 1s

Cll i
cons1de1cJ, the macron1okculJr structure 1s rc prtscnted 3S follow~ :

II Cl h I! CH1 H CH ,

C = C C -C C-C”

vv- C
1
H! CH : CH , CH : CH : CH , ‘””‘

llus~tructu rc tllustr:ll cs th:it the methrl gro11p,;;1re orirnted m o ne direction about the carbon-
carbo n douhtr bond~ . Nature sek’Ct1H ly product’S only thens-iso mer of 1,4- polyisoprcne.

Styren e

ru bbe r • Aflynatur.tl
Or!lynthetkpolymer
that l!l!l;mult11neou1ly
elutk,11 !n ight. water-
re11!!1tant. and
long-wear ing

nalu r1l rub bH • Th e
po lymer producC’d from
thc latextl1a tuude1
fromcut1 l ntheb1rkof
theSouthAmcriun
rubb er tree

Chapter 14 Chem istry of Some Polymer ic M ater \al~ 637

LL

v,.,lcan,z,itlon • Tho!!
proc,uofconvtrt,ng
the-rmopl ;,, nic11J bbf’< \ tothtrmos@n1ngn.,b. l>@flbyhut,ngth,m
with , lem @nt;,,lsuth.,,
orc@rt• ,nsulh.,1 –
bunngcompoundsto
produc, d,wlf,d, uon-
linlting bondswith ,n
stgm@nUoithl!r
m”

B} 11sdf, n.uur.il rubber 1s nut <'llt1TCI) d<'s1r.1blc fo r prod uct um of con1rnerci,1 I u-.1' . 11 1, soft .inJ ~11d.:.), ('Spr-cull)' 111 ,1 :nm c\un.lll' ) . ln 1839, h1.1\\e\'t'r, ChJrle\ P1oJ )t·.ir .1cc1d emJ!ly d1K01~·r<'d 111.11 1h<' ~ und es 1r:1Mc fc.ituu.•s cou ld be d11111 nJted b . h~ the 11.1t u~1I rubix.r "1th cle mc.-n ul s ulfur. Th is di scovery, c:illeJ vulcanization , !~J ;:11r1g uhmlJI (' d<'\<'lupmcm of S) mhct1 c rubber~ . !~,

,\1 {h<' nuc romolC'Cul.ir lc 1<'I, 1uk.1mz.1t1011 IS a chemic.ii proC<'SS 11hc-rc-in th

~:~:~;~

1

:,:;;~~:o~:;u~;~~t;!: ‘~:<'11~~::~f~~~~:~~-~1~~;:s~o 1:.1t.1~tfJ~e\\~:,ructi~r;';f 1 1t

CH , CH,

w CJI C,= CH – CH1 ~ H – C CH – Cl\ :””

‘
CH , C! h

•i-iM·•f:iMfii·it

V\llu rr ia dn.i bb.r
• Anyonur;r, lor
synthtt1crubbt’rlh .tt
hu ~” vulumu•d

fyflthttic ru bbtr • Any
polymu produc~ from
1ubn.Jnctsothulh•n,
or,n•dd ttionto.the
lnulrc,mth,South
Aml!nUon.,bb,rtr,e
.rndh,ivmgproP@rtJ4!”S
s,m,!,irtothos@ofn•t-
uralru bber

::e.”‘=’ ::=P¥c::~,r: .~:~1~ ::~;~,1: ~;nd:e~~~~ ~~:~~e•n~: ~~ng ~ ankH, ¥qf–:-,
~olutlon: Foam rubbl!r OtOt 1ubbe1 and i fl ,ncru1e , r, 1u !urt.i« “”‘._
8y«l<'llast ar> ntrtgJ-S,Sf”Otf’f’t’ilPOl!dw1t,-.u,e f\J bbe-r us•d form, prodL1ct,on of 111bber~rfS ActeePf1nt o~s out:•”l!d ·n ~,on 5 5·8 .,,, •ncruse ,n u,e surf•c,a•••of thtrueuinu 1no,asesthere«t0t, ~
8e-uu,.,, thf n.,bbe, ,., fo.m ‘1,,tlbl!r P’od”‘U l\iS .t grta”l!f w rf.tee arta th¥l \hf ‘Ybbl!r 1n nJbbfr tires. fo.mll,0-
~• Pro

Rubber manufacwrcrs usu.i lly Jcceler.it e the rll<' ac whi c h th<')' vulcJmze rublxr 1hrough the Jddmon of subu:ances hkc- tttram<'thylth1uramd1sulfidc, i1nc d1eth)·ldnh10- carb.im.1tc-, d1ph e11)•hh1ourca, or peroxo-orgarnc compounds .

Each resultmg product 1s c.illc-d a vukanlud rubb e r. It 1s toughc.-r, harde r, bs pla snc anJ
sucky, Jnd more elasuc compued to unvulcamzed rubber. Vuka111zcd rublx:r ,s Jlso cap,1bkof
ret:urung a firm shape over a rc-bmclr wide tempcnnur<' range-. Vuk.an1z.1uon also pmnris the casting of 11.1tural rubber mto unique sh.a~ suc h u automobile rires. A m1xrure of rubber. carbon, and sulfur 1s mst'ned into a mold that, when S<'a!ed and h<'a tcd, produces a tire ClrtalS.

14 .1 1-B SYNTHETIC RUBBERS
:-.JJtural rubber still accoum s fo r lpprox1ma1cl y 35% of the- dema nd for rubber in tht
Umtc-d States. Today, however, th e world no longer rehes solely on the huo· from rubber
trees for llS rubb e r. Chem1su have sy mhe s,zed elasromc-rs called synthe t ic rubbers . The1t
have physical propcmes s1m1lar to or bc-m·r 1h:1n rh osc of natura l rublx-r. \’l;’c- hndl)’ notr
the propemes of fi,·e synthetic rubbers: cis- 1.4- polybutadicne rubber, s tyrenc–b11tadirnr
tubbc-r, acrylornmlc-bu1ad1e11e rubber, neoprt nc, and pol rs ulf1dt rubh<'r.

638 Chaptu 14 Ch,m istry of Somt Polym,r ic M•ttrials

• ci , ~i~-:~:~,~•.:•~~:~;’:~s11~ ‘.~<'~ ::'~jlc~I ~)fllhe11c rubber. h 1s pruducl·d by the polym - c11tJ OOrl ~roi~iolc-cul<' s liowu !iow ~r-~ ,lll.l CJtJl)st , In th e 1wo-d1m cns 1011,1l segmcm ;:ri~:/~~-

1
le h)droi;cn atonh arc locattd un the same side uf

CII – CJI } l-l = CH CH C1I Cli ‘= CII CH = CH
– CH Cl! : Ci t: lH ! \Cf\ ~ CH! .,.,.,.

r1£· 1,4•1’ol ybuiadicne h,is m;iny of !he prop,:rt1r s of nJtural rubber and mar b<' vulc.imied ._. 1th rk111rn1,il sulfur. It IS u~d m the- produc-t1on and mJnufacture of \thicub r urts .

• Sty((!ne-butaditnt rubb,r (SBR J \\JS f1r\t known as GRS (gmemme m rubber
,f\rrnd, ll(‘(ause II was produ cc-d on beh.ilf of 1hr U.S. milllary dmmg \’<"orld War II. &r,,:ausc 111 s a copol) mtr of 1,3-buudicnc- and St)rtne, 11 b«-ame known outsid<' go1em - ~nl c1rdrs :i s Buna S ( Bu for buudm1e, Na fo r sod1m11, and S fur styrene ). (The produc- 1,00 rracuon 1s cat.ilyud by sodium .) The rtptaung uni t of SBR 1s rc-prc-sentcd as follow s:

[-1C11, – CH = CH – CH, ),

6
C11,-[.

SB R 1s ,·ulc,u11zed usmg c-lt’mental sulfu r. lkc.1use it rc-s1sts W<'Jr more 1h a11 any o ther syn- ihc11c rubber, SBR is usc-d IO nunufoctute mos1 tire lrC'J.ds . h also is the m3jor component ofniJ n)' JdhM1vcs.

Buna N ruh hc-r is a copolymer uf bu1.id1cne and ac11 lumtnle (N U.tnds for mt,1/e ).
It is also known as ac rylomt nl c-butJd1(‘nc rubbn. The- rc-pc.:itmg unit m lluna N rub bc-r
1111\tfol\owmg:

BunJ N rubber h:is 1hc uni que fe ature of v. uhs1andmg hcJt up to 350°F ( 177• ( ); othc-r
s,ntheuc rubber s softc-11, melt, or burn a1 lowc-t temp,:ra turcs .

• Pol)ch\oroprene 1s mor(‘ commonl y known as n,op r,ne. It 1s a chlonnared rubber
rroduced b)· heating chloropr<'ne, or 2-chloro· l,3•but ad1t'ne, :l knowo human carcmo- gcn. The s unpl csr Stru ctur<' of the- rc-pcJtmg umt 1n neoprene is 1h e followmg:

C
[“””- CH!-1=CH-CH: .,.,…,.._].

Cl

\ w prmc- 1s 1uk:imzt’d wuh zmc- ox1d<', durmg 11 htch smglc nc-oprenc strJnds c ross-lmk v.1th OX)gc-n :icoms and rc-pb cc some of the chlorme atoms. ~bcromolc-c ular segme nt s o f th, 1ukam1.ed nc.-oprcn c hJ\'C 1wo- d1mrn>1on .1l suuctu r(‘S such as th e followmg:

Cl

,…… CH: – C = C ll\1

0
CH :· C = C – CII ,–“‘”‘

ti

styre ne- bu tad ltnf
r~bb t r • Th, synlhet •< rubbuprodu

n, oprt n, • Asyothet,c
@lastom,rcompo1t’dol
rn -1,4-oolychloropr@n,

2-Ch1oro-1,3 –
but1dl101

Ch1ptu 14 Chl!m imy of Som, Polymenc Mat, rl als 639

..t,onite A form of
h• rdrubber u5edpr1 –
mar1ly tom•ke thec•, –
mgsfor •utomob,l e
stor•geb• ner,e~

FI GU RE 14.8 Some
corimonoroduttimo!de
e-therctrt’Ctlyfn:im11JDbtf
or from other polymers
conti,no11<,rubber

:-; …..,pr,..nc rubber d, ,c-s not po>~e~s 1h,.. rt~1htn(t ue,cs~,1ry fo r use m tire s, but 11 ,s >cr”lc
JHe \\Jtt rpn,ol JnJ chemica\h r<."~1, tJ nt to JXlroleum produ , n and o zone . This I h mll..~s 11 ~u u Jb le. for , p('(i.11 111:J u;,c-s suc h a> roo fin g nle. flexible ho se, ,,eisuiis r eatur,
,hoes. compute r-m … u,,.. pJ ds. ,PoJ holder s, and other prod ucts . ‘ un m.”lg

11llJS ~ c:~~~l:~: ~t~:~.1~1~:·:: 16~~~1; : ~!~~:1:~~ ~~;t:’::t; ~~:1 ft~1~::, er.1l t) r>es, tbc
CH • CH :· ‘ ‘> I,

”
It” u~ d pr,m.1n ly to m.rnufa,mre ho ses for 111semng g.1sohrn.• :md rnl into , om.1ine~

1 4. 1 1-C CO NSUM ER P ROD UCTS PRODU CED F RO M
SYNTHET IC RU BB ERS

S)’nthc-n..: rubbers ,ukanued wuh sulfur or sulfur compounds arc used to manufacr1.1rrJ
,·.1nety o f products, some of whw;h are 11lusm:ue

• Narnral rubber mixed w11h onl y 3% sulfur by mass IS soh and el.1>tic . It 1s UScd for
m.1nuf.:K1uring inner cubes and rubber bands.

~!~1:~::1h:~1~ u’;::1~t s~~t~~y~s~l:~dt;~~a::1asc::rri:;~:,~~:::
When rubber h.1s b«n ,•ukamzed so that It conums 68 % sulfu r b)” 11\JSS, it beco111ts
a black solid ,.a iled e bon lte. o r hard nibber. It is used to mJke black pm10 kc)HnJ
the casings for lead-a,1d storage b.1tteries.

Othe r substances that :ire component s of rubber formul:111ons mdude the follo”in g:

• C ar bon bl.1ck 1s ofie n added as a remforcmg f,lkr to make rubber stronger, abra-
sive, and eas ier IO elongate, and to pre,tnt It from breakmg and tea rin g.

Silica f,llers are added IO prov,de surfo,e ab rasion IO rubbe r intended for u~ in
vehKularures .

640 Chilpter 14 Chemistry of Some Po lymeric Mater ials

• o istitlate•a romatic -e11 tract oils (DAE o,l s) M e added to !.Often rubbe r before ,t s u~e.
ihn ,Kl J ~ p1.hUCll cr~ during procei;~ ,ng.. Thnr addition to >e h1cullr tin: formul.i11u11s

‘~-~ r ro”de, 1111pruH•d rnfnrm,mce chJTJclnlS\ic,; like M”et ~,p~ 10 ro .,d ~urf.Kn. DAF.
l 1. JrC pnxl ue!s of th e p,·trok um refo1mg indus try. The)” ,ons,st ol nm,uires o f h1gh-ho1l111i;
‘:~,r-iu m!> nic l11J1ng pol) nud e Jr aromJ11c h)drocarbon~. In 20 10, DAE oils \\ere b.u111cd
:n urr> 1ntendc-J fo r use m the European Un, on; henle, altcmJmc products h.iv1ni; surnl.ir

rrt>~ rt:~~:f’.;~k~~170
1

~::1cir~~:·:~~;;~~=de~:~~;r~~:~~~:•l;·t!
1
r’:b~:~~~~;~1d1:~::~;I:~

~, l:J~~;\1:fi1~ :e;v,::~cr:1%:e~b~:·of the rubber produ ct. a,r or amnmmum ca rhon.1tc
JISJl inl ) l,c nu>;cJ 11110 the rubbe r la te x. When thi s n11x1ure subsequem! )’ 1s heJted, 1he
lmnio mlllll ca rbonate decompmes IO ammom;i :ind carbon d1ox1de. These gases hc,0111,·
entrJpped w1d1111 t he ,omplex rub bc:r ~rructure as II hJrdens. The product. cJ\led foam
r11bbtr, 1s u>ed to nunu foctu 1e cushions and mattres \.e s.

• In the \\Jrm climates ol 1he south\\~le m ~1J1es, pre1·1ouslr u~d rubber 1s pull’er-

;::h:~i 1~
1
::::~•i;:r ~::u~~~c:!

1

~:d~~:;.;~~d~;~~hca;~m~r;a~\~~~i~~~o~~~~:i~=~

11
uS(d c-1scwherc . Ru bberucd asphah , annot be used suc,essfull)’ for the s.i.me purpo<;C" ,n

Jros of the Umtcd Sutes that expe rience cold c\m1ates durmg 1he wmter momhs, he, .1usc
11 J,xs not survwc the 1mpJ(t of , h.1ms and snowplo\\ S,

14.11 · 0 RESPONDING TO INCIDENTS INVOLVING
THE BURNING OF RUBBER

To undc rsi.md the natur e of 1hc subsrnn,es pr odu,ed when rubbrr product s bu m . 1t 1~
oe-ess.1q· 10 recollect the gencr.il features of their che m1cal fo rmu 1Jt1ons. Durin g the
combu>tto n process, the co nsmuents of these furmulatmns comh1ne wnh atmospheric
o~n;rn 111 th e £0ll01, mg wa ys:

di1t1ll 1le-u om1tl< ••U-• cto ll s

Pet1oleum -b11ed
produtU

A
1pongyrub berpro·
du

As they burn , rubber produ(tS ,uka nu ed wuh suliur or sulfu r-bea rin g com pound~
prod u,c ca rbon monoxide, sulfu r d1ox1d e, and water ,apor.

1 The smoke a1soc1.1 tcd “uh rubber firei; 1s cx1raordmanly dense and black, as m th e
scene dep1c1c

FI GU R E 14 .9 A foe
,,,,11,,11 a mass,ve p,le ot
veh1clet,resmi1~ be ,n,1o –
att-a byal,gt1tf”l·ng\\l •ke
Astrc i.re\burn, lf1e
smol,;etr1at”olves1\
,11ten~ely den~ar,d bl.Kt
To b.,rgtnost,;oeolf,re
unde•co111ro11heu\eOI
1oec,al t,re e<1,ngu,~hers gene•il'I~ ,s rea..i,red ICour~olfyorro' 7f'<""o/c)Q,es, rnc. ""°"-oe. V,

Chapter 14 Ch em\stry of Some Polymem Milte r,als 641

I

r
I

The smoke associ a 1cd with rubber tires is highl y toxic, not only beca use of the
encc of toxic gases like carbo n mono xi de and sulfur dioxide, but also due to th e pres-
ence of the PAH s added in DAE oils. pres-
As neoprene burns, carbon monoxide, water vapor; and hydrogen chloride arc produced
As polysulfide rubber burns, carbon monoxide, sulfur dioxide, and water va~r ,
arc produced .
. Beca~sc the atmos phere nea r burning rubber consists of a mi~ture of these gases, the

to x1c environment of th e sce ne must be acknowledged when selecting a proper fircfighti
strategy. The dense, black smok e associated with rubber fires is composed largely of a~:
borne carbo n particles. Because soot is a known h uma n carcinogen, brea thing it could
initiate long-term adverse heahh effects. To prevent or reduce fata li ties among firrfighters
th e use of self-con tained breathing apparatus always is warran ted . ‘

642 Chapter 14 Chemistry of Some Polymeric Materials