Термодинамічне визначення температури склування полімерів

Abstract

The possible solution of the classical problem of correct determining the glass transition temperature of polymers is proposed. The equation for the correlation between the glass transition temperature and the cooling rate of polymeric glass-forming media is suggested on the basis of combination of thermodynamic formalism and the ideas of relaxation kinetics. The parameters of that kinetic equation are determined and tabulated for a number of glass-forming substances covering sufficiently wide class of pure and modified polymers, in particular polyvinyls, polyesters, and polydienes. The possibility of the manifestation of an anomalous dependence of the glass transition temperature on the cooling rate is substantiated. It is suggested that the observable anomalies in the kinetics of the glass transition arise from considerable inertance of the segments of polymeric macromolecules, i.e. are of threshold nature.