Effect of branching on the physical characteristics of polymers

Abstract

The effects of the length and character of the branching distribution on a number of physical characteristics of polymers, i.e. the glass transition temperature, the coefficient of bulk thermal expansion, the refractive index, the Hildebrand solubility parameter, and the surface energy are analysed. It is calculated that short chain branches have the greatest effect on the physical characteristics, since they lead to a significant change in the chemical structure of the polymer system. The effect of long chain branching depends on the differences in their chemical structure from that of the main chain and to a lesser extent on the degree of long chain branching. The physical characteristics of the polymer show the sharpest changes when tree-like branching occurs.