Deck 26: Synthetic Polymers

Question 1

"Super" glues are typically composed of what polymer?

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

Answer 1

poly(methyl a-cyanoacrylate)

Question 2

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)

Answer 2

poly(vinyl chloride)

Question 3

What monomer is needed to produce the polymer below?

Answer 3

acrylonitrile,

Question 4

________ 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.

Question 5

Most pop bottles are made from this type of polymer: ________.

A) PETE
B) PVC
C) PP
D) LDPE

Question 6

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 7

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

Question 8

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

Question 9

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

Question 10

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

Question 11

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 12

Draw the structure of poly(acrylonitrile).

Question 13

Which of the following is not an addition polymer?

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

Question 14

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

Question 15

_{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

Question 16

Plexiglas is a:

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

Question 17

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 18

_{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 19

Provide the structure of poly(isobutylene).

Question 20

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

Question 21

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 22

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

Question 23

Predict the monomer units that combine to form polyurethane.

Question 24

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

Question 25

Provide the structure of the monomer from which poly(methyl α-methacrylate) is formed.

Question 26

In polymerization reactions what purpose does benzoyl peroxide usually serve?

Question 27

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

Question 28

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

Question 29

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

Question 30

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 31

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

A)

B)

C)

D)

Question 32

Provide the structure of Teflon.

Question 33

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

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

Question 34

Explain why H₂C=CHCO₂CH₃ does not undergo cationic polymerization.

Question 35

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 36

Provide the structure of poly(methyl α-methacrylate).

Question 37

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

Question 38

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

Question 39

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 40

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

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

Question 41

Provide the structure of syndiotactic polypropylene.

Question 42

Provide a representation of atactic polypropylene.

Question 43

Provide a representation of atactic poly(acrylonitrile).

Question 44

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

Question 45

Provide the structure of atactic polypropylene.

Question 46

Provide a representation of syndiotactic polystyrene.

Question 47

Show the reaction which occurs when benzoyl peroxide is heated.

Question 48

Provide the structure of syndiotactic polystyrene.

Question 49

Provide the structure of isotactic polystyrene.

Question 50

Provide a mechanism for the free-radical polymerization of styrene. The radical initiator may be symbolized by I∙.

Question 51

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 52

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 53

Provide a representation of syndiotactic polypropylene.

Question 54

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

Question 55

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

Question 56

Provide the structure of atactic polystyrene.

Question 57

Provide the structure of isotactic polypropylene.

Question 58

Provide a representation of isotactic poly(acrylonitrile).

Question 59

Provide a representation of isotactic polystyrene.

Question 60

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 61

Polymers composed of identical monomer units are known as ________.

Question 62

Which type of polymerization most commonly results in branched, atactic polymers: anionic, cationic or free-radical?

Question 63

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

Question 64

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 65

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

Question 66

Another name for a urethane is a(n):

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

Question 67

Nylon 6 is a:

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

Question 68

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

Question 69

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 70

Dacron is a:

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

Question 71

The stereochemistry observed in this polymer is described as ________.

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

Question 72

How does vulcanization of rubber alter its structure and properties?

Question 73

Provide the structure of natural rubber.

Question 74

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

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

Question 75

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 76

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 77

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

Question 78

Natural rubber is a:

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

Question 79

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

Question 80

What are copolymers?