24
Organic
Chemistry
William H. Brown &
Christopher S. Foote
24-1
24
Organic
Polymer
Chemistry
Chapter 24
24-2
24 Organic Polymer Chem.
 Polymer:
from the Greek, poly + meros, many
parts
• any long-chain molecule synthesized by bonding
together single parts called monomers
 Monomer:
from the Greek, mono + meros, single
part
• the simplest nonredundant unit from which a polymer
is synthesized
 Plastic:
a polymer that can be molded when hot
and retains its shape when cooled
24-3
24 Organic Polymer Chem
 Thermoplastic:
a polymer that can be melted and
molded into a shape that is retained when it is
cooled
 Thermoset plastic: a polymer that can be molded
when it is first prepared but, once it is cooled,
hardens irreversibly and cannot be remelted
24-4
24 Notation & Nomenclature
 Show
the structure by placing parens around the
repeat unit
• n = average degree of polymerization
synthesized
from
n synthesized
from
Cl
Polystyrene
Styrene
n
Poly(vinyl chloride)
(PVC)
Cl
Vinyl
chloride
24-5
24 Notation & Nomenclature
 To
name a polymer, prefix poly to the name of the
monomer from which the it is derived
• if the name of the monomer is one word, no parens are
necessary
• for more complex monomers or where the name of the
monomer is two words, enclose the name of the
monomer is parens, as for example poly(vinyl chloride)
or poly(ethylene terephthalate)
24-6
24 Molecular Weight
 All
polymers are mixtures of individual polymer
molecules of variable MWs
• number average MW: count the number of chains of a
particular MW, multiply each number by the MW, sum
these values, and divide by the total number of
polymer chains
• weight average MW: record the weight of each chain of
a particular length, sum these weights, and divide by
the total weight of the sample
24-7
24 Morphology
 Polymers
tend to crystallize as they precipitate or
are cooled from a melt
 Acting to inhibit crystallization are their very
large molecules, often with complicated and
irregular shapes, which prevent efficient packing
into ordered structures
 As a result, polymers in the solid state tend to be
composed of ordered crystalline domains and
disordered amorphous domains
24-8
24 Morphology
 High
degrees of crystallinity are found in
polymers with regular, compact structures and
strong intermolecular forces, such as hydrogen
bonds and dipolar interactions
• as the degree of crystallinity increases, the polymer
becomes more opaque due to scattering of light by the
crystalline regions
 Melt
transition temperature, Tm: the temperature
at which crystalline regions melt
• as the degree of crystallinity increases, Tm increases
24-9
24 Morphology
 Highly
amorphous polymers are sometimes
referred to as glassy polymers
• because they lack crystalline domains that scatter
light, amorphous polymers are transparent
• in addition they are weaker polymers, both in terms of
their greater flexibility and smaller mechanical
strength
• on heating, amorphous polymers are transformed from
a hard glass to a soft, flexible, rubbery state
 Glass
transition temperature, Tg: the temperature
at which a polymer undergoes a transition from a
hard glass to a rubbery solid
24-10
24 Morphology
 Example:
poly(ethylene terephthalate),
abbreviated PET or PETE, can be made with %
crystalline domains ranging from 0% to 55%
O
O
O
O
n
Poly(ethylene terephthalate)
24-11
24 Morphology
 Completely
amorphous PET is formed by cooling
the melt quickly
• PET with a low degree of crystallinity is used for
plastic beverage bottles
 By
prolonging cooling time, more molecular
diffusion occurs and crystalline domains form as
the chains become more ordered
• PET with a high degree of crystallinity can be drawn
into textile fibers and tire cords
24-12
24 Step-Growth Polymers
 Step-growth
polymerization: a polymerization in
which chain growth occurs in a stepwise manner
between difunctional monomers
 we discuss five types of step-growth polymers
•
•
•
•
•
polyamides
polyesters
polycarbonates
polyurethanes
epoxy resins
24-13
24 Polyamides

Nylon 66 (from two six-carbon monomers)
O
HO
OH +
O
Hexanedioic acid
(Adipic acid)
H 2N
N H2
heat
1,6-Hexanediamine
(Hexamethylenediamine)
O
O
N
H
Nylon 66
H
N
n
• during fabrication, nylon fibers are cold-drawn to
about 4 times their original length, which increases
crystallinity, tensile strength, and stiffness
24-14
24 Polyamides
• the raw material base for the production of nylon 66 is
benzene, which is derived from cracking and reforming
of petroleum
3 H2
catalyst
Benzene
O2
catalyst
Cyclohexane
O
OH
+
Cyclohexanol
HN O 3
Cyclohexanone
COOH
COOH
Hexanedioic acid
(Adipic acid)
24-15
24 Polyamides
• adipic acid is in turn the starting material for the
synthesis of hexamethylenediamine
O
N H4
+ -
O
O - N H4 +
heat
O
Ammonium hexanedioate
(Ammonium adipate)
O
H 2N
N H2
O
Hexanediamide
(Adipamide)
4 H2
catalyst
H 2N
N H2
1,6-Hexanediamine
(Hexamethylenediamine)
24-16
24 Polyamides
 Nylons
are a family of polymers, the two most
widely used of which are nylon 66 and nylon 6
• nylon 6 is synthesized from a six-carbon monomer
O
n
N H 1. partial hydrolysis
Caprolactam
H
O
N
2. heat
n
Nylon 6
• nylon 6 is fabricated into fibers, brush bristles, highimpact moldings, and tire cords
24-17
24 Polyamides
 Kevlar
is a polyaromatic amide (an aramid)
O
nHOC
O
COH
1,4-Benzenedicarboxylic
acid
(Terephthalic acid)
O
C
+ nH 2 N
NH2
1,4-Benzenediamine
(p-Phenylenediamine)
O
CNH
Kevlar
NH
n
+
2 nH 2 O
• cables of Kevlar are as strong as cables of steel, but
only about 20% the weight. Kevlar fabric is used for
bulletproof vests, jackets, and raincoats
24-18
24 Polyesters
 Poly(ethylene
terephthalate), abbreviated PET or
PETE, is fabricated into Dacron fibers, Mylar
films, and plastic beverage containers
O
O
+
HO
OH
heat
HO
OH
1,4-Benzenedicarboxylic acid 1,2-Ethanediol
(Ethylene glycol)
(Terephthalic acid)
O
O
O
O
n
Poly(ethylene terephthalate)
(Dacron, Mylar)
+ 2 nH2 O
24-19
24 Polyesters
• ethylene glycol is obtained by air oxidation of
ethylene followed by hydrolysis to the glycol
CH2 = CH2
Ethylene
O
O2
catalyst
CH2 -CH 2
Oxirane
(Ethylene oxide)
H+ , H2 O
HOCH2 CH2 OH
1,2-Ethanediol
(Ethylene glycol)
• terephthalic acid is obtained by catalyzed air
oxidation of petroleum-derived p-xylene
H3 C
CH3
p-Xylene
O
O
O2
COH
catalyst HOC
Terephthalic acid
24-20
24 Polycarbonates
 Lexan
is a tough transparent polymer with high
impact and tensile strengths and retains its
shape over a wide temperature range
• it is used in sporting equipment, such as bicycle,
football, and snowmobile helmets as well as hockey
and baseball catcher’s masks
• it is also used in the manufacture of safety and
unbreakable windows
24-21
24 Polycarbonates
• to make Lexan, an aqueous solution of the sodium salt
of bisphenol A is brought into contact with a solution
of phosgene in CH2Cl2 in the presence of a phasetransfer catalyst
O
CH3
+
Na - O
CH3
Disodium salt
of Bisphenol A
O- Na + + Cl
Cl
Phosgene
O
CH3
O
CH3
Lexan
(a polycarbonate)
O
n
+ 2 NaCl
24-22
24 Polyurethanes
A
urethane, or carbamate, is an ester of carbamic
acid, H2NCH2COOH
• they are most commonly prepared by treatment of an
isocyanate with an alcohol
O
RN = C= O +
An isocyanate
R' OH
RN HCOR'
A carbamate
 Polyurethanes
consist of flexible polyester or
polyether units (blocks) alternating with rigid
urethane units (blocks)
• the rigid urethane blocks are derived from a
diisocyanate
24-23
24 Polyurethanes
• the more flexible blocks are derived from low MW
polyesters or polyethers with -OH groups at the ends
of each polymer chain
O= C=N
CH3
N = C= O + nHO- polymer-OH
Low-molecular-weight
polyester or polyether
2,6-Toluene
diisocyanate
O
CN H
CH 3
O
N HCO- polymer- O
n
A polyurethane
24-24
24 Epoxy resins
 Epoxy
resins are materials prepared by a
polymerization in which one monomer contains
at least two epoxy groups
• within this range, there are a large number of
polymeric materials, and epoxy resins are produced in
forms ranging from low-viscosity liquids to highmelting solids
24-25
24 Epoxy Resins
• the most widely used epoxide monomer is the
diepoxide prepared by treating 1 mole of bisphenol A
with 2 moles of epichlorohydrin
CH 3
O
O - Na +
+ Na + - O
Cl
Epichlorohydrin
CH 3
the disodium salt of
bisphenol A
CH 3
O
O
O
O
CH 3
A diepoxide
24-26
24 Epoxy Resins
• treatment of the diepoxide with a diamine gives the
resin
CH3
O
O
O
O
CH3
A diepoxide
NH 2
H2 N
A diamine
CH3
OH
O
OH
O
CH3
An epoxy resin
H
N
N
H n
24-27
24 Thermosets
 Baelekite
was one of the first thermosets
OH
OH
+ CH2 O
Phenol
OH
OH
Formaldehyde
OH
OH
Baekelite
24-28
24 Chain-Growth Polymers
 Chain-growth
polymerization: a polymerization
that involves sequential addition reactions, either
to unsaturated monomers or to monomers
possessing other reactive functional groups
 Reactive intermediates in chain-growth
polymerizations include radicals, carbanions,
carbocations, and organometallic complexes
24-29
24 Chain-Growth Polymers
 We
concentrate on chain-growth polymerizations
of ethylene and substituted ethylenes
R
An alkene
R
n
• on the following two screens are several important
polymers derived from ethylene and substituted
ethylenes, along with their most important uses
24-30
24 Polyethylenes
Monomer
Formula
Common
Name
Polymer Name(s) and
Common Uses
CH2 = CH2
Ethylene
Polyethylene, Polythene;
break-resistant containers
and packaging materials
CH2 = CHCH 3
Propylene
Polypropylene, Herculon;
textile and carpet fibers
CH2 = CHCl
Vinyl chloride
Poly(vinyl chloride), PVC;
construction tubing
CH2 = CCl 2
1,1-Dichloroethylene
Poly(1,1-dichloroethylene),
Saran; food packaging
24-31
24 Polyethylenes
CH2 = CHCN
Acrylonitrile
Polyacrylonitrile, Orlon;
acrylics and acrylates
CF2 = CF2
Tetrafluoroethylene
Poly(tetrafluoroethylene),
PTFE; nonstick coatings
CH2 = CHC6 H5
Styrene
Polystyrene, Styrofoam;
insulating materials
CH2 = CHCOOEt
Ethyl acrylate
CH2 = CCOOCH 3
Methyl
methacrylate
Poly(ethyl acrylate);
latex paints
Poly(methyl methacrylate),
Plexiglas; glass substitutes
CH3
24-32
24 Radical Chain-Growth
 Among
the initiators used for radical chaingrowth polymerization are diacyl peroxides,
which decompose as shown on mild heating
O
O
O

O
Dibenzoyl
peroxide
O
2
A benzoyloxy
radical
O
2
+ 2 CO 2
A phenyl
radical
24-33
24 Radical Chain-Growth
 Another
common class of initiators are azo
compounds, which also decompose on mild
heating or with absorption of UV light
 or h
N C
:
:
N N
C N
Azoisobutyronitrile (AIBN)
2
•
N C
+ : N N:
Alkyl radicals
24-34
24 Radical Chain-Growth
 Radical
polymerization of a substituted ethylene
• chain initiation
 or h 
In-In
In
2 In
+
In
R
R
• chain propagation
In
In
+
R
+
In
R
R
R
R
In
n
R
R
R
n
R
etc.
24-35
24 Radical Chain-Growth
• chain termination
radical
coupling
In
R
2 In
R
n
n
R R
In
n
R
R
disproportionation In
R
n
+
R
H
In
R
n
R
24-36
24 Radical Chain-Growth
 Radical
reactions with double bonds almost
always gives the more stable (the more
substituted) radical
• because additions are biased in this fashion,
polymerizations of vinyl monomers tend to yield
polymers with head-to-tail linkages
R
R
R
R
R
R
R
R
head-to-tail linkages
R
R
head-to-head linkage
24-37
24 Radical Chain-Growth
 Chain-transfer
reaction: the reactivity of an end
group is transferred from one chain to another,
or from one position on a chain to another
position on the same chain
• polyethylene formed by radical polymerization exhibits
a number of butyl branches on the polymer main chain
• these butyl branches are generated by a “back-biting”
chain-transfer reaction in which a 1° radical end group
abstracts a hydrogen from the fourth carbon back
• polymerization then continues from the 2° radical
24-38
24 Radical Chain-Growth
H
A six-membered transition
state leading to
1,5-hydrogen abstraction
H
nCH2 = CH2
n
24-39
24 Radical Chain-Growth
 The
first commercial polyethylenes produced by
radical polymerization were soft, tough polymers
known as low-density polyethylene (LDPE)
• LDPE chains are highly branched due to chain-transfer
reactions
• because this branching prevents polyethylene chains
from packing efficiently, LDPE is largely amorphous
and transparent
• approx. 65% is fabricated into films for consumer
items such as baked goods, vegetables and other
produce, and trash bags
24-40
24 Ziegler-Natta Polymers
 Ziegler-Natta
chain-growth polymerization is an
alternative method that does not involve radicals
• Ziegler-Natta catalysts are heterogeneous materials
composed of a MgCl2 support, a Group 4B transition
metal halide such as TiCl4, and an alkylaluminum
compound
CH2 = CH2
Ethylene
T iCl
4/
Al( CH2 CH3 ) 2 Cl
Mg Cl2
n
Polyethylene
24-41
24 Ziegler-Natta Polymers
 Mechanism
of Ziegler-Natta polymerization
Step 1: formation of a titanium-ethyl bond
Mg Cl2 / TiCl 4
particle
Ti
Cl
+
Cl
Cl A l
Ti
+
Cl A l
Diethylaluminum
chloride
Step 2: insertion of ethylene into the Ti-C bond
Ti
+
CH2 = CH2
Ti
24-42
24 Ziegler-Natta Polymers
 Polyethylene
from Ziegler-Natta systems is
termed high-density polyethylene (HDPE)
• it has a considerably lower degree of chain branching
than LDPE and a result has a higher degree of
crystallinity, a higher density, a higher melting point,
and is several times stronger than LDPE
• appox. 45% of all HDPE is blow-molded into containers
• with special fabrication techniques, HDPE chains can
be made to adopt an extended zig-zag conformation.
HDPE processed in this manner is stiffer than steel
and has 4x the tensile strength!
24-43
24 Polymer Stereochemistry
 There
are three alternatives for the relative
configurations of stereocenters along the chain
of a substituted ethylene polymer
R H R H R H
R H R H
Isotactic polymer
(identical configurations)
R H
H R R H
H R R H
Syndiotactic polymer
(alternating configurations)
R H R H R H
R H
H R
Atactic polymer
(random configurations)
24-44
24 Polymer Stereochemistry
 In
general, the more stereoregular the
stereocenters are (the more highly isotactic or
syndiotactic the polymer is), the more crystalline
it is
• the chains of atactic polyethylene, for example, do not
pack well and the polymer is an amorphous glass
• isotactic polyethylene, on the other hand, is a
crystalline, fiber-forming polymer with a high melt
transition
24-45
24 Ionic Chain-Growth
 May
be either anionic or cationic polymerizations
• cationic polymerizations are most common with
monomers with electron-donating groups
OR
Styrene
Isobutylene
Vinyl ethers
SR
Vinyl thioethers
• anionic polymerizations: most common with
monomers with electron-withdrawing groups
CN
Styrene
COOR
Alkyl
methacrylates
COOR
Alkyl
acrylates
CN
Acrylonitrile
COOR
Alkyl
cyanoacrylates
24-46
24 Anionic chain-Growth
 Anionic
polymerization can be initiated by
addition of a nucleophile, such as methyl lithium,
to an activated alkene
R'
R'
R
Li +
R'
R
+
Li
+
R'
R
R'
etc.
24-47
24 Anionic Chain-Growth
 An
alternative method for initiation involves a
one-electron reduction of the monomer by Li or
Na to form a radical anion which is either
reduced or dimerized to a dianion
Li
Li
+
Butadiene
A radical anion
radical coupling
to form a dimer
Li
Li
+
Li
Li
A dimer dianion
+
+
Li
+
+
A dianion
24-48
24 Anionic Chain-Growth
 To
improve the efficiency of anionic
polymerizations, soluble reducing agents such
as sodium naphthalide are used
+ Na
THF
N a+
:
Naphthalene
Sodium naphthalide
(a radical anion)
• the naphthalide radical anion is a powerful reducing
agent and, for example, reduces styrene to a radical
anion which couples to give a dianion
24-49
24 Anionic Chain-Growth
Na +
Styrene
Na +
Na +
Na +
A s tyryl
radical anion
A dis tyryl dianion
• the styryl dianion then propagates polymerization at
both ends simultaneously
24-50
24 Anionic Chain-Growth
 propagation
of the distyryl dianion
1. 2n
N a+
N a+ 2 . H O
2
A distyryl dianion
n
n
Polystyrene
24-51
24 Anionic Chain-Growth
 Living
polymer: a polymer chain that continues
to grow without chain-termination steps until
either all of the monomer is consumed or some
external agent is added to terminate the chains
• after consumption of the monomer under living
anionic conditions, electrophilic agents such as CO2 or
ethylene oxide are added to functionalize the chain
ends
24-52
24 Anionic Chain-Growth
• termination by carboxylation
:
n
N a+
CO 2
n
COO- Na +
H3 O +
n
COOH
24-53
24 Cationic Chain-Growth
 The
two most common methods for initiating
cationic polymerization are
• reaction of a strong protic acid with the monomer
• abstraction of a halide from the organic initiator by a
Lewis acid
 Initiation
by a protic acid requires a strong acid
with a nonnucleophilic anion in order to avoid
addition to the double bond
• suitable acids include HF/AsF5 and HF/BF3
24-54
24 Cationic Chain-Growth
• initiation by a protic acid
R
R
R
H+ BF 4 -
H3 C
R
+ BF4 R
R
H3 C
R R RR
n
+ R
BF4 -
R
• Lewis acids used for initiation include BF3, SnCl4,
AlCl3, Al(CH3) 2Cl, and ZnCl2
24-55
24 Cationic Chain-Growth
• initiation
Cl + SnCl 4
+ SnCl 5 -
2-Chloro-2-phenylpropane
• propagation
+
+
+
2-Methylpropene
n
+
n
+
24-56
24 Cationic Chain-Growth
• chain termination
n
+
H2 O
SnCl 5 -
n
OH
+ H+ SnCl 5 -
24-57
24 Prob 24.5
Name each polymer, and draw the structure of the
monomer(s) that might be used to make it.
(a)
n
(b)
O
n
(c)
n
O
(d)
O
(f)
O
n
O
O
O
(g)
n
CF2
n
CF3
O
(e)
CF
n
H
N
(h)
O
O
N n
H
CH2 Cl
24-58
24 Prob 24.7
Draw a structural formula for the polymer formed in each
reaction.
O
O
(a) Me O
OMe + HO
O
O
(b) Me O
(c)
O
OH
H+
OH
OMe + HO
CF3 SO3 H
OH
H+
(d)
O
KOH
24-59
24 Prob 24.8
Propose reagents and experimental conditions for the
conversion of furan to hexamethylenediamine.
oat hulls, corn
H 2 SO 4
cobs, sugar cane
H2 O
stalks, etc
(1)
O
Furan
Zn-Cr-Mo
catalyst
O
O CH
Furfural
(2)
O
Tetrahydrofuran
(THF)
N C( CH2 ) 4 C N
Hexanedinitrile
(Adiponitrile)
Cl( CH2 ) 4 Cl
(3)
1,4-Dichlorobutane
(4)
H2 N( CH 2 ) 6 N H 2
1,6-Hexanediamine
(Hexamethylenediamine)
24-60
24 Prob 24.9
Propose reagents for the conversion of 1,3-butadiene to
hexamethylenediamine.
CH2 = CHCH = CH 2
Butadiene
(1)
ClCH 2 CH= CHCH2 Cl
(2)
1,4-Dichloro-2-butene
N CCH2 CH= CHCH2 C N
3-Hexenedinitrile
(3)
H2 N( CH 2 ) 6 N H2
1,6-Hexanediamine
(Hexamethylenediamine)
24-61
24 Prob 24.10
Propose reagents and experimental conditions for the
conversion of butadiene to adipic acid.
?
1,3-Butadiene
H OOC
COOH
Hexanedioic acid
(Adipic acid)
24-62
24 Prob 24.12
Propose a mechanism for the step-growth reaction in this
polymerization.
O
n CH3 OC
O
COCH 3 +
Dimethyl terephthalate
O
C
275°C
nHOCH2 CH 2 OH
Ethylene glycol
O
COCH 2 CH2 O
n
Poly(ethylene terephthalate)
+
2 nCH3 OH
Methanol
24-63
24 Prob 24.13
Identify the monomer(s) required for the synthesis of
each step-growth polymer.
(a)
O
C
O
C-O- CH2
CH2 O
n
Kodel
(a polyester)
(b)
O
O
C( CH2 ) 6 C N H
CH2
NH
n
Quiana
(a polyamide)
24-64
24 Prob 24.14
Draw a structural formula for the repeating unit of Nomex.
H 2N
N H2
+
1,3-Benzenediamine
Cl
Cl
polymerization
Nomex
O
O
1,3-Benzenedicarbonyl chloride
24-65
24 Prob 24.15
Propose a mechanism for this Beckmann rearrangement
which converts cyclohexanone oxime to caprolactam, the
monomer from which nylon 6 is synthesized.
O
N
OH
N H2 OH
Cyclohexanone
Cyclohexanone
oxime
O
H2 SO 4
NH
Caprolactam
24-66
24 Prob 24.17
Propose a mechanism for the formation of this
polycarbonate.
O
F + N a2 CO 3
F
An aromatic
difluoride
Sodium
carbonate
O
O
O
O n + 2 N aF
A polycarbonate
24-67
24 Prob 24.18
Propose a mechanism for the formation of this polyurea.
To simplify, consider the reaction of one -NCO group with
one -NH2 group.
OCN
N CO +
1,4-Benzenediisocyanate
H 2N
N H2
1,2-Ethanediamine
O
O
H
N
N
N N
n
H
H H
Poly(ethylene phenylurea)
24-68
24 Prob 24.19
When equal molar amounts of these two monomers are
heated, they form an amorphous polyester. Under these
conditions, polymerization is regioselective for the 1°-OH
groups. Draw a structural formula for the repeat unit of
this polyester.
O
OH
O + HO
O
Phthalic
anhydride
OH
heat
a polyester
1,2,3-Propanetriol
(Glycerol)
24-69
24 Prob 24.21
Propose a mechanism for formation of this polymer.
O
O
O
O
base
+
H2N
N H2
N
N
n
24-70
24 Prob 24.22
Draw a structural formula for the polymer resulting from
base-catalyzed polymerization of each monomer. Will the
polymer by optically active?
O
(a)
O
O
O
(S)-(+)-Lactide
(b)
O
(R)-Propylene oxide
24-71
24 Prob 24.23
The polymer on the left is an insoluble, opaque material
that is difficult to process into shapes. The polymer on
the right is an transparent material that is soluble in a
number of organic solvents. Explain the difference in
physical properties between the two in terms of their
structural formulas.
O
O
O
n
Poly(3-hydroxybutanoic acid)
O
On
O
m
Poly(3-hydroxybutanoic acid 3-hydroxyoctanoic acid) copolymer
24-72
24 Prob 24.25
Draw a structural formula for the repeat unit of the
polymer formed in each reaction.
(a)
O
O
Li
AIBN
70°C
(b)
CN
24-73
24 Prob 24.26
Select the member of each pair that is more reactive
toward cationic polymerization.
(a)
(b)
or
OCH3
OCH3
(c)
(d) CH3 O
or
OCCH 3
O
or
or
24-74
24 Prob 24.33
Natural rubber is the all-cis polymer of isoprene. Draw a
structural formula for the repeat unit of natural rubber.
Poly(2-methyl-1,3-butadiene)
(Polyisoprene)
24-75
24 Prob 24.34
Radical polymerization of styrene gives a linear polymer.
Show by drawing structural formulas how incorporation
of a few percent 1,4-divinylbenzene in the polymerization
mixture gives a cross-linked polymer.
+
Styrene
a copolymer of styrene
and divinylbenzene
1,4-Divinylbenzene
24-76
24 Prob 24.37
From what two monomer units is this polymer made?
C N
C N
24-77
24 Prob 24.38
Draw a structural formula for the repeat unit in the
polymer formed by ring-opening metathesis
polymerization of each monomer.
O
(a)
(b)
(c)
O
(d)
24-78
24
Organic
Polymer
Chemistry
End Chapter 24
24-79