ABSTRACT
The motion of low molecular particle introduced into polymer matrix correlates with that of kinetically independent elements of macromolecules surrounding the particle. Setting of rigorous quantitative descriptions of this connection is a complicated problem, and approaches to its solution are in progress. This chapter discusses in brief the modern ideas on the mechanism of relaxational processes, based on segmental dynamics of macromolecules. The spectrum of relaxation times in polymers embraces a wide range of frequencies and is continuous-discrete, i.e. consists of overlapping peaks of separate relaxational processes. A specific feature of the polymer state, in terms of molecular dynamics, is primarily observed in the relaxational processes associated with the motion of large molecular aggregates, chain segments linked with crystalline regions, as well as in the parameters of distribution in molecular mobility. The bulk compression of polymers is accompanied by an increase in the glass transition temperature and relaxation times of molecular motions.
