THE FORMATION AND PROPERTIES OF THREE-DIMENSIONAL POLYMERS: III. THE EFFECT OF NETWORK STRUCTURE ON ELASTIC PROPERTIES

Abstract

The tension exerted by stretched rubber at a given temperature and elongation is determined by the initial molecular weight and the concentration of cross-linkages. With the copolymer of butadiene and styrene (GR-S) the effect of molecular weight on elastic properties is identical with that found by Flory for butyl rubber and arises from the inactivity of terminal chains. When the molecular weight is fixed, the retractive force is approximately linear with the degree of cross-linking, in agreement with the statistical mechanics of rubber elasticity.