Deck 26: Synthetic Polymers

Question 1

Which of the following is the best initiator for a free-radical polymerization?

A) BuLi
B) PhOH
C) (PhCO₂)₂
D) CH₃CH(OCH₃)₂
E) BF₃

Answer 1

(PhCO₂)₂

Question 2

_{Which of the following is the best initiator for an anionic polymerization?}

A) BuLi
B) PhOH
C) (PhCO₂)₂
D) CH₃CH(OCH₃)₂
E) BF₃

Answer 2

BuLi

Question 3

________ polymers result from rapid reaction of one molecule at a time with a growing polymer chain, usually with a reactive intermediate at the growing end of the chain.

A) Addition
B) Condensation
C) Step-growth
D) Amorphous

Answer 3

Addition

Question 4

"Super" glues are typically composed of what polymer?

A) poly(acrylonitrile)
B) poly(methyl α-cyanoacrylate)
C) polystyrene
D) polypropylene
E) poly(methyl α-methylacrylate)

Question 5

________ polymers result from polymerization reactions in which chain growth is accompanied by loss of a small molecule.

A) Addition
B) Condensation
C) Chain-growth
D) Latex

Question 6

What monomer is needed to produce the polymer below?

Question 7

Provide the structure of the monomer from which polystyrene is formed.

Question 8

The monomer shown below, 1,1-bistrifluoromethylethylene, undergoes polymerization via:

A) anionic polymerization
B) cationic polymerization
C) radical polymerization
D) chain-growth polymerization

Question 9

Plexiglas is a:

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

Question 10

Is the polymer shown an addition polymer or a condensation polymer?

Question 11

Provide the structure of the monomer from which Teflon is formed.

Question 12

Which of the following is not an addition polymer?

A) polyethylene
B) Orlon
C) Plexiglas
D) Kevlar
E) Teflon

Question 13

Provide the structure of poly(isobutylene).

Question 14

Which of the following monomers is most well-suited to cationic polymerization?

A) isobutylene
B) ethylene
C) acrylonitrile
D) methyl α-methacrylate
E) methyl α-cyanoacrylate

Question 15

What is the carbon : hydrogen mole ratio in polyethylene?

A) 12:1
B) 1:2
C) 1:3
D) 3:2
E) 1:100

Question 16

Ethylene oxide can be polymerized to form Carbowax. What conditions are best for the polymerization of ethylene oxide?

A) anionic
B) cationic
C) free-radical
D) carbene
E) none of the above

Question 17

_{Which of the following is the best initiator for a cationic polymerization?}

A) BuLi
B) PhOH
C) (PhCO₂)₂
D) CH₃CH(OCH₃)₂
E) BF₃

Question 18

Draw the structure of poly(acrylonitrile).

Question 19

From which of the following are water pipes commonly manufactured?

A) poly(methyl α-cyanoacrylate)
B) polyurethane
C) poly(acrylonitrile)
D) poly(vinyl chloride)
E) poly(isobutylene)

Question 20

Provide the structure of the monomer from which polypropylene is formed.

Question 21

When ethylene is polymerized by free-radical initiation, what type of polyethylene is formed?

A) low-density; highly branched
B) low-density; unbranched and highly linear
C) high-density; highly branched
D) high-density; unbranched and highly linear
E) high-density; highly crystalline

Question 22

Propose a synthesis of poly(vinyl alcohol) from

Question 23

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

Question 24

Super glue shown below is most likely constructed under what type of mechanism?

A) radical
B) cationic
C) anionic
D) condensation

Question 25

Provide the structure of Teflon.

Question 26

The mechanism by which poly(methyl α-cyanoacrylate) formed was most likely ________.

A) anionic addition
B) cationic addition
C) radical addition
D) condensation

Question 27

Draw the structure of the polymer produced in the following reaction.
CH₃CH
CH₂

Question 28

Provide the structure of the monomer from which
is formed.

Question 29

Explain why H₂C
CHCO₂CH₃ does not undergo cationic polymerization.

Question 30

In polymerization reactions what purpose does benzoyl peroxide usually serve?

Question 31

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

Question 32

Provide the structure of the monomer from which poly(vinyl chloride) is formed.

Question 33

Which of the following is the monomer unit of the polymer shown below?

A)
B)
C)
D)

Question 34

Which of the following monomers is least readily polymerized under conditions of anionic polymerization?

A) isobutylene
B) acrylonitrile
C) methyl acrylate
D) methyl α-cyanoacrylate
E) methyl α-methacrylate

Question 35

Styrene undergoes polymerization via what type of mechanism?

A) anionic polymerization
B) cationic polymerization
C) radical polymerization
D) It will polymerize via all three mechanisms.

Question 36

Provide the structure of the monomer from which poly(acrylonitrile) is formed.

Question 37

Predict the monomer units that combine to form polyurethane.

Question 38

Which of the following is least readily formed by cationic polymerization?

A) poly(acrylonitrile)
B) poly(isobutylene)
C) poly(propylene)
D) polystyrene
E) All of the above have equal propensity to undergo cationic polymerization.

Question 39

Poly (vinyl acetate) is used in the backing of carpet, and in paints and adhesives. Provide two repeating units of poly (vinyl acetate).

Question 40

Show each step in the mechanism for the following transformation. Include all intermediates and be sure to use arrows correctly to indicate placement of electrons.

Question 41

An alternating copolymer is shown below. Is this an addition polymer or a condensation polymer?

Question 42

If the side groups of a polymer occur randomly on either side of the polymer backbone, then the polymer is called ________.

A) atactic
B) syndiotactic
C) isotactic
D) enantiotactic
E) randiotactic

Question 43

Draw three repeating units of poly(vinyl chloride), having syndiotactic stereochemistry.

Question 44

Maleic anhydride (below) undergoes chain-growth polymerization but not step-growth polymerizations. Why not?

Question 45

Maleic anhydride (below) undergoes addition polymerization. Draw the structure of the polymer that results.

Question 46

An alternating copolymer is shown below. What two monomers were used to make this polymer?

Question 47

Why can't poly(vinyl alcohol) be synthesized directly from vinyl alcohol as shown below?

Question 48

Provide the structure of isotactic polystyrene.

Question 49

Show the reaction which occurs when benzoyl peroxide is heated.

Question 50

Provide the structure of syndiotactic polystyrene.

Question 51

If the side groups of a polymer chain are generally on the same side of the polymer backbone, the polymer is called ________.

A) atactic
B) syndiotactic
C) transiotactic
D) cisisotactic
E) isotactic

Question 52

Provide the structure of isotactic polypropylene.

Question 53

Provide a representation of atactic poly(acrylonitrile).

Question 54

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

Question 55

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

Question 56

Provide the structure of atactic polypropylene.

Question 57

Provide the structure of syndiotactic polypropylene.

Question 58

Neoprene is a flexible, chemically resistant polymer used in shoe soles, hoses and wetsuits. Based on the polymer structure of neoprene, provide a structure for the monomer of neoprene.

Question 59

Provide the structure of atactic polystyrene.

Question 60

Provide a representation of isotactic poly(acrylonitrile).

Question 61

Which of the following polymers can be classified as copolymers?

A) 1 & 2
B) 2 & 4
C) 1 & 4
D) 2 & 3
E) 1, 3, & 4

Question 62

Provide the structure of natural rubber.

Question 63

Polymers composed of identical monomer units are known as ________.

Question 64

Another name for a urethane is a(n) ________.

A) carbamate ester
B) carbonate ester
C) orthoester
D) aryl diisocyanate
E) carbamic acid

Question 65

What type of polymer is formed from ethylene glycol and a diester as monomer components?

A) polyurethanes
B) polyamides
C) polyesters
D) polycarbonates
E) none of the above

Question 66

How does vulcanization of rubber alter its structure and properties?

Question 67

Provide the structure of Saran, an alternating copolymer of
and

Question 68

Named for a pair of Nobel Prize winners, ________ catalysts, which are composed of aluminum- and titanium-containing Lewis acids, provide a high measure of stereocontrol in alkene polymerizations.

Question 69

What substance results from the 1,4-polymerization of 1,3-butadiene?

Question 70

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

Question 71

Cis-1,4-Polybutadiene is one form of synthetic rubber. Provide the structure of this polymer.

Question 72

Dacron is a ________.

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

Question 73

The stereochemistry observed in this polymer is described as ________.

A) atactic
B) isotactic
C) syndiotactic
D) tacky
E) regiotactic

Question 74

What are copolymers?

Question 75

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

Question 76

Natural rubber is a ________.

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

Question 77

Shown below is a segment of polypropylene. Which of the following terms describes the stereochemistry of the methyl substituents?

A) atactic
B) isotactic
C) syndiotactic
D) tacky
E) peritactic

Question 78

The structure of cellulose is shown below. What type of polymer is it?

A) Alternating copolymer
B) Chain-growth polymer
C) Step-growth polymer
D) Ziegler-Natta polymer

Question 79

Which of the following elements is necessary for the vulcanization of rubber?

A) sulfur
B) silicon
C) phosphorus
D) boron
E) titanium

Question 80

Nylon 6 is a ________.

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