Effect of Side‐Group Interactions on the Mean Dimensions of Vinyl Polymers

Abstract

Mean‐square end‐to‐end distances for stereoregular vinyl polymers with interacting side groups are calculated. It is found that the steric interaction of the side groups always results in a shrinkage of the molecule as a whole, the effect being more pronounced for the syndiotactic conformation. As the side‐group diameter increases, both isotactic and syndiotactic polymers tend to a limiting configuration which is probably helical. It is proposed that the difference in the degree of shrinkage between isotactic and syndiotactic polymers may be used as a criterion for measuring tacticity of partially tactic polymers.