Deck 27: Synthetic Polymers

Question 1

Which of the following addition polymers results from the reaction below? nCF₂
CF₂
?

A)[ CF-CF ]_n
B)[CF₃-CF₃]_n
C)[-CF₂-CH CHCF₂-]_n
D)[-CF₂-CF₂-]_n
E)[-CF₂ CF₂-]_n

Answer 1

[-CF₂-CF₂-]_n

Question 2

Which of the following monomers has the greatest ability to undergo cationic polymerization?

A)I
B)II
C)III
D)IV
E)V

Answer 2

III

Question 3

List the two major classes of synthetic polymers and give one example of each.

Answer 3

a)Addition polymers,also known as chain-growth polymers; polystyrene for example. b)Condensation polymers,also known as step-growth polymers; nylon for example.

Question 4

Which of the following is the first chain propagating step in the radical polymerization of ethylene?

A)ROOR + CH₂ CH₂ → ROCH₂CH₂OR
B)∙ RO∙ + CH₂
CH₂ → ROCH₂CH₂
C)RO∙ + CH₂ CH₂ → ROCH CH₂ + H∙
D)∙ ∙ ROOR + CH₂
CH₂ → 2 ROH + CH CH
E)∙ ∙ 2RO∙ + CH₂
CH₂ → 2 ROH + CH CH

Question 5

Which of the following is the chain-initiating step in the cationic polymerization of propene?

A)I
B)II
C)III
D)IV
E)V

Question 6

Which of the following is a possible step to terminate a chain in the radical polymerization of ethylene?

A)ROOR + CH₂ CH₂ → ROCH₂CH₂OR
B)CH₂ CH₂ + CH₂
CH₂ → CH₃CH CHCH₃
C)∙ RO∙ + CH₂
CH₂ → ROCH₂
CH₂
D)∙ ∙ ROCH₂CH₂ + CH₂
CH₂ → ROCH₂CH₂CH₂CH₂
E)∙ 2 RO-[CH₂CH₂]_n-CH₂CH₂ →
RO-[CH₂CH₂]_n-CH₂CH₂CH₂CH₂-[CH₂CH₂]_n-OR

Question 7

Chain-growth polymerization proceeds by which of the following mechanisms?

A)radical polymerization
B)cationic polymerization
C)anionic polymerization
D)A and B
E)A,B,and C

Question 8

Which of the following species can best serve as an initiator for anionic polymerization?

A)CH₃CH₂CH₂CH₂Li
B)BF₃
C)HOOH
D)CH₃CH₂CH₂CH₂OH
E)CH₃CH₂CH₂CH₂OCH₂CH₂CH₂CH₃

Question 9

Which of the following statements best describes what alpha olefins are?

A)polysubstituted ethylenes
B)monosubstituted ethylenes
C)disubstituted ethylenes
D)ethylenes
E)isoprenes

Question 10

Which of the following species can best serve as an initiator for cationic polymerization?

A)ROOR
B)ROH
C)ROR
D)AlCl₃
E)RCOOR

Question 11

The choice of mechanism in chain-growth polymerization depends on which of the following?

A)structure of the monomer and initiator used
B)structure of the polymer and initiator used
C)temperature and pressure of the reaction
D)A and B
E)A,B,and C

Question 12

What is the structure of the monomer from which the following polymer is made?

A)I
B)II
C)III
D)IV
E)V

Question 13

What is the structure of the monomer from which the following polymer is made?

A)CH₃CH₃
B)CH₂ CH₂
C)CH₃CH CH₂
D)CH₂ CHCH CH₂
E)CH₃CH CHCH₃

Question 14

Draw the structure of the polymer and by-product that result when the two monomers below are heated together.

Question 15

Which of the following is more likely to undergo both radical and cationic polymerization?

A)I
B)II
C)III
D)IV
E)V

Question 16

Which of the following are characteristic of linear polyethylene?

A)They are branched polymers.
B)They are known as high-density polyethylene.
C)They are soft and flexible polymers.
D)A and B
E)A and C

Question 17

Chain-growth polymerization exhibits a marked preference for

A)tail-to-tail addition
B)head-to-head addition
C)head-to-tail addition
D)head-to-middle addition
E)middle-to-tail addition

Question 18

Which of the following monomers has the greatest ability to undergo anionic polymerization?

A)I
B)II
C)III
D)IV
E)V

Question 19

Which of the following species can best serve as a radical initiator for radical polymerization?

A)ROH
B)ROR
C)ROOR
D)RCOOR
E)RCOOH

Question 20

Which of the following statements best explains the process known as chain transfer?

A)a process that can control the rate of production of the polymer
B)a process that can control the molecular weight of the polymer
C)a process that can control the reactivity of the monomer
D)a process that can slow down the polymerization reaction
E)a process that can inhibit the polymerization reaction

Question 21

From which of the following compounds is Lucite or poly(methyl methacrylate)prepared?

A)CH₂ CHCH₃
B)CH₂ C(CH₃)O₂CCH₃
C)CH₂ CHO₂CCH₃
D)CH₂ C(CH₃)CO₂CH₃
E)CH₂ CHCO₂CH₃

Question 22

List the three phases in the mechanism of chain-growth polymerization.

Question 23

Which is not typically made through radical polymerization?

A)poly(styrene)
B)PVC
C)Dacron
D)poly(vinyl acetate)
E)Lucite

Question 24

In a recycling symbol,the ________ the number in the middle of the symbol,the more easily the compound can be recycled.

Question 25

Propose a synthesis of poly(vinyl alcohol)from H₂C CHO₂CCH₃.

Question 26

Which of the following is more likely to form non-terminated polymeric chains called living polymers?

A)cationic polymerization
B)free radical polymerization
C)anionic polymerization
D)A and B
E)A and C

Question 27

When 2,2-dimethyloxirane (see figure below)undergoes anionic polymerization,the nucleophile attacks the least substituted carbon of the epoxide,but when it undergoes cationic polymerization,the nucleophile attacks the most substituted carbon of the epoxide.Explain why this is so.

Question 28

When 3-methyl-1-butene
CH₂
CHCH(CH₃)₂
undergoes cationic polymerization,the following expected carbocation is formed.
⊕
X-CH₂-CH-CH(CH₃)₂
However,the following carbocation is also found in the reaction.
⊕
X-CH₂-CH₂-C(CH₃)₂
Explain.

Question 29

What structural characteristic is shared by compounds used as radical initiators?

Question 30

Show how branching could occur during the free-radical polymerization of styrene.

Question 31

What are common factors that enter into the choice of radical initiators for chain-growth polymerization?

Question 32

Provide a mechanism to show how H₂C CHCO₂CH₃ is polymerized using butyllithium as the initiator.

Question 33

Which of the following monomers is least likely to undergo cationic polymerization?

A)propylene
B)isobutylene
C)styrene
D)methyl acrylate
E)vinyl acetate

Question 34

Explain why some monomers are better able to undergo chain-growth polymerization by a radical mechanism.

Question 35

Provide a mechanism to show how H₂C C(CH₃)₂ is polymerized using BF₃ as the initiator.

Question 36

Show the mechanism for the formation of a segment of polystyrene containing two molecules of styrene and initiated by hydrogen peroxide.

Question 37

Which of the following can result in chain termination in cationic polymerization?

A)loss of H+
B)addition of a nucleophile that reacts with the propagating site
C)a chain transfer reaction with the solvent
D)a 1,2-hydride shift.
E)A,B,and C

Question 38

Show the three methods by which the following radical can be terminated.

Question 39

Show the reaction which occurs when benzoyl peroxide is heated.

Question 40

Provide the structure of the monomer from which Orlon [poly(acrylonitrile)] is prepared.

Question 41

Draw the monomer for poly(vinyl acetate).

A)
B)
C)
D)
E)

Question 42

Provide the structure of poly(propylene).

Question 43

What is the main structural difference between high-density and low-density polyethylene,and how does this structural difference affect the properties and uses of these polymers?

Question 44

Draw the structure of the polymer that results when methyl α-cyanoacrylate undergoes polymerization.By what name is this polymer commonly known?

Question 45

Identify the monomer(s)that undergo anionic polymerization.You may choose more than one answer.

A)styrene
B)methyl methacrylate
C)vinyl chloride
D)methyl vinyl ether
E)acrylamide

Question 46

Provide the structure of poly(vinyl chloride).

Question 47

Give the monomer for the polymer teflon.

A)propylene
B)acrylonitrile
C)tetrafluoroethylene
D)poly(vinyl acetate)
E)styrene

Question 48

Identify the initiator in a radical polymerization.

A)KOH
B)BuLi
C)CH₃OOCH₃
D)BF₃,H₂O
E)HCl

Question 49

Identify the monomer for superglue.

A)acrylamide
B)methyl a-cyanoacrylate
C)acrolein
D)methyl vinyl ether
E)styrene

Question 50

Draw a short segment of neoprene,using four monomers.

Question 51

Is acrylonitrile more likely to undergo anionic or cationic polymerization? Explain your answer.

Question 52

Identify the monomer(s)that undergo cationic polymerization.You may choose more than one answer.

A)styrene
B)methyl methacrylate
C)vinyl chloride
D)methyl vinyl ether
E)acrylamide

Question 53

What advantage does a Lewis acid like BF₃ have over a proton-donating acid like HCl as a initiator in cationic polymerization?

Question 54

Why is chain branching less common in anionic polymerization than in cationic polymerization?

Question 55

Provide the structure of poly(acrylonitrile).

Question 56

Draw a short segment of plexiglass,using five monomers.

Question 57

Identify the initiator in a cationic polymerization.

A)KOH
B)BuLi
C)CH₃OOCH₃
D)BF₃,H₂O
E)HCl

Question 58

Identify the initiator in an anionic polymerization.

A)KOH
B)BuLi
C)CH₃OOCH₃
D)BF₃,H₂O
E)HCl

Question 59

What is the mass of each repeating unit in poly(ethylene)?

Question 60

Identify the monomer(s)that undergo radical polymerization.You may choose more than one answer.

A)styrene
B)methyl methacrylate
C)vinyl chloride
D)methyl vinyl ether
E)acrylamide

Question 61

The pattern below is found in what type of polymer? AABBBABAABABBAAB

A)an alternating copolymer
B)a block copolymer
C)a random copolymer
D)a graft copolymer
E)a homopolymer

Question 62

Draw the structure of the polymer produced in the following reaction.

Question 63

ABS is a copolymer of what three monomers?

Question 64

Identify the type of polymer for nylon 66.

A)homopolymer
B)graft copolymer
C)random copolymer
D)block copolymer
E)alternating copolymer

Question 65

The pattern below is found in what type of polymer? AAAABBBBAAAABBBB

A)an alternating copolymer
B)a block copolymer
C)a random copolymer
D)a graft copolymer
E)a homopolymer

Question 66

Provide the structure of Saran,an alternating copolymer of H₂C CHCl and H₂C CCl₂.

Question 67

Which of the following polymers is arranged in an isotactic configuration?

A)I
B)II
C)III
D)IV
E)V

Question 68

Natural rubber is a

A)polyamide.
B)polyester.
C)polycarbonate.
D)polyurethane.
E)none of the above.

Question 69

From which of the following monomers is neoprene synthesized?

A)(Z)-2-chloro-2-butene
B)(E)-2-chloro-2-butene
C)(E)-1-chloro-1,3-butadiene
D)2-chloro-1,3-butadiene
E)2,3-dichloro-1,3-butadiene

Question 70

What are aramides?

A)aromatic polyester polymers
B)aromatic amine polymers
C)alkyl halide polymers
D)aromatic polyamide polymers
E)aliphatic polyamide polymers

Question 71

Identify the type of polymer for poly(vinyl chloride).

A)homopolymer
B)graft copolymer
C)random copolymer
D)block copolymer
E)alternating copolymer

Question 72

What is the difference between natural rubber and Gutta-percha rubber?

A)Natural rubber is hard and brittle while gutta-percha is soft and rubbery.
B)Natural rubber is natural while gutta-percha is synthetic rubber.
C)Natural rubber has a cis configuration while gutta-percha has a trans configuration.
D)Natural rubber and gutta-percha rubber are enantiomers.
E)The monomer for natural rubber is isoprene while the monomer for gutta-percha is 1,3-butadiene.

Question 73

Kevlar is an example of

A)a polyester.
B)an aramide.
C)a polyurethane.
D)a epoxy resin.
E)a plasticizer.

Question 74

Which of the following statements best describes what vulcanization means?

A)a process by which rigid and non-sticky rubber can be made soft and sticky
B)a chemical process discovered by Charles Schultz in 1944
C)the heating of rubber with sulfur
D)a chemical process that destroys cross-linking in rubber
E)all of the above

Question 75

Provide the structure of poly(tetrafluoroethylene).

Question 76

Which of the following statements concerning the stereochemistry of polymerization is correct?

A)Polymers in the atactic configuration are more likely to be crystalline solids because regular packing of the polymer chains is easier.
B)Polymers in the isotactic configuration tend to be softer and more flexible than atactic polymers.
C)In general,radical polymerization leads primarily to branched polymers in the syndiotactic configuration.
D)The percentage of chains in the isotactic or syndiotactic configuration decreases as the polymerization temperature decreases.
E)none of the above

Question 77

Which of the following is a step-growth polymer?

A)polyethylene
B)polyester
C)polypropylene
D)polystyrene
E)Plexiglass

Question 78

A substituted ethylene polymer in which the substituents are randomly oriented is called

A)a ditactic polymer.
B)an eutatic polymer.
C)an isotactic polymer.
D)a syndiotatic polymer.
E)an atactic polymer.

Question 79

Name the monomer used in the production of neoprene.

Question 80

Which of the following initiators are known as Ziegler-Natta catalysts,which were discovered in 1953 in order to control the stereochemistry of polymers?

A)Al/Ti initiators
B)Ni/Cd initiators
C)Zn/Hg initiators
D)Pb/C initiators
E)Pb/PbO₂ initiators