Thermal Expansion and Compressibility of Amorphous Polymers

Abstract

Structure insensitive properties of amorphous polymers are discussed on the basis of cell model. Even in amorphous polymer, each polymer chain is supposed to be surrounded by six or four nearest neighbors and they form a hexagonal or tetragonal lattice. Lennard-Jones type potential is assumed between chain units which belong to different chains. The equation of state is obeys the principle of corresponding state. Considering the growth of holes due to the micro-Brownian motions of the chain segments, the dependences of specific volume and compressibility on temperature are discussed for rubbery state as well as glassy one. The results fairly agree with available experimental data.