Polymer Conformation
In order for a polymer to crystallize it must he ahle to assume
a regular conformation, i.e., the three-dimensional arraneement
of the .oo lv.m er backbone as produced by rotation
about the honds must he regular. ~ol~&h~lefnore e,x ample,
crvstallizes in a fullv-extended, planar zig-zag conformation
(Fig. 4). Polymers kith short, bulky substituents that are
regularly spaced along the chain often assume a helical conformation
in the crystalline phase. This allows the suhstituents
to pack closely together without any appreciable distortion
of the chain bonds. Amorphous polymers, on the other
hand, tend to exist in completely random conformation