Chapter 4

Question 1

Most polymers are hydrocarbons. (T or F)

Answer 1

True

Question 2

saturated hydrocarbons

Answer 2

each carbon is singly bonded

Question 3

polyethylene

Answer 3

a long-chain hydrocarbon

Question 4

degree of polymerization

Answer 4

number of repeating monomeric units in a polymer

Question 5

Polymer properties depend on what four things?

Answer 5

1. Chemistry
2. Size
3. Structure
4. Shape

Question 6

thermoplastics

Answer 6

polymers that solidify as they cool and “flow” when they are heated

Question 7

thermosets

Answer 7

polymers that solidify by a chemical curing process

Question 8

molecular weight

Answer 8

mass of a mole of chains

Question 9

isomerism

Answer 9

two compounds with the same chemical formula can have quite different structures

Question 10

stereoisomerism

Answer 10

mirror images of polymers

Question 11

tacticity

Answer 11

stereoregularity or spatial arrangement of R units along chain

Question 12

isotactic

Answer 12

all R groups on same side of chain

Question 13

syndiotactic

Answer 13

R groups alternate sides

Question 14

atactic

Answer 14

R groups randomly positioned

Question 15

amorphous

Answer 15

polymer chains are randomly coiled about each other with entanglements

Question 16

semi-crystalline

Answer 16

polymer chains are packed together into regular structural patterns

Question 17

crosslink

Answer 17

polymer chains are covalently lined together

Question 18

Amorphous properties

Answer 18

-atactic
-linear, branched
-transparent, flexible, tough, low shrinkage, low density

Question 19

Semi-crystalline properties

Answer 19

-syndiotactic, isotactic
-linear, small branching
-opaque, brittle, high density

Question 20

Crosslink properties

Answer 20

-networked
-rigid, hard, brittle, high melting points

Question 21

copolymers

Answer 21

two or more monomers polymerized together