Fundamentals of Materials Science and Engineering: An Integrated Approach, 3e

GTBL042-04 GTBL042-Callister-v2 September 26, 2007 1:46

2nd Revise Page

118 • Chapter 4 / Polymer Structures

Table 4.5 Chemical Repeat Units That Are Employed in Copolymer Rubbers

Repeat Unit Repeat Unit Repeat Unit Repeat Unit

Name Structure Name Structure

VMSE

Repeat Units

Rubbers Acrylonitrile

H

CC

H

H

C N

Isoprene

H

CC

H H

CH 3 H

CC

H

Styrene

H

CC

H

H

Isobutylene

H

CC

H

CH 3

CH 3

Butadiene

H

CC

H H

H H

CC

H

Dimethylsiloxane Si O

CH 3

CH 3

Chloroprene

H

CC

H H

Cl H

CC

H

0.741 nm

CH

0.494 nm

0.255 nm

Figure 4.10 Arrangement of

molecular chains in a unit cell

for polyethylene. (Adapted

from C. W. Bunn,Chemical

Crystallography,Oxford

University Press, Oxford,

1945, p. 233.)