Question 1

Which of the following best describes the difference between chain-growth and step-growth polymerization?

Accepted Answer

Chain-growth polymerization involves the rapid addition of monomers to a growing chain via reactive intermediates, while step-growth polymerization involves the gradual combination of monomers, often with the loss of a small molecule such as water or methanol.

Question 2

Which polymer is commonly used for making nonstick cookware coatings and cable insulation?

Accepted Answer

Poly(tetrafluoroethylene) (Teflon)

Question 3

What is the repeating unit of polystyrene, a chain-growth polymer formed from styrene monomers?

Accepted Answer

$$\mathrm{-(CH_2$-CH(Ph))-}_n$$

Question 4

Which of the following monomers would most likely undergo anionic polymerization?

Accepted Answer

Methyl methacrylate ($$\mathrm{CH_2$=C(CH_3$)$$COOCH_3$$})$$

Question 5

Which of the following statements about the head-to-tail addition in chain-growth polymerization is correct?

Accepted Answer

It is favored because it minimizes steric hindrance and stabilizes the propagating site.

Question 6

Which of the following is a real-world application of poly(acrylonitrile)?

Accepted Answer

Rugs, blankets, and simulated fur

Question 7

A plasticizer is added to a polymer to:

Accepted Answer

Make it more flexible

Question 8

Which of the following best explains why branched polymers are more flexible than linear polymers?

Accepted Answer

Short branches disrupt close packing, reducing crystallinity and increasing flexibility.

Question 9

Which of the following is a step-growth polymer used for making wrinkle-resistant clothing and transparent bottles?

Accepted Answer

Polyethylene terephthalate (Dacron)

Question 10

Which of the following statements about the recycling of polyethylene terephthalate (PET) is correct?

Accepted Answer

It involves the reverse of the transesterification reaction that formed the polymer.

Question 11

Which of the following is a property of thermosetting polymers?

Accepted Answer

They are cross-linked and become more rigid with increased cross-linking.

Question 12

Which of the following best describes the role of a radical initiator in radical polymerization?

Accepted Answer

It provides radicals that react with the alkene monomer to initiate polymerization.

Question 13

Which of the following monomers is used to produce Super Glue via anionic polymerization?

Accepted Answer

Methyl $$\alpha-$$cyanoacrylate

Question 14

Which of the following statements about Kevlar is correct?

Accepted Answer

It is a polyamide with aromatic rings, making it five times stronger than steel by weight.

Question 15

Which of the following is true about the effect of crystallinity on the properties of polyethylene?

Accepted Answer

Higher crystallinity increases density, melting point, and heat resistance.

Question 16

Which of the following is a correct example of a copolymer and its use?

Accepted Answer

ABS (acrylonitrile, butadiene, styrene) – used for bumpers and crash helmets

Question 17

Which of the following best explains why epoxides are more reactive than ethers in acid-catalyzed ring-opening polymerization?

Accepted Answer

Epoxides are strained three-membered rings, making them more susceptible to nucleophilic attack.

Question 18

Which of the following is a biodegradable polymer used in medical applications such as sutures and drug delivery systems?

Accepted Answer

Polylactic acid (PLA)

Question 19

Which of the following statements about the mechanism of cationic polymerization is correct?

Accepted Answer

The initiator is an electrophile, often a Lewis acid with a proton-donating base, that generates a carbocation.

Synthetic Polymers: Structure, Mechanisms, and Applications

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