Study of molecular mobility in filled and unfilled crosslinked organosilicon rubbers

Abstract With the aid of dielectric and dynamic mechanical methods a study has been made of the extent to which molecular mobility in crosslinked organosilicon rubbers is influenced by thermal prehistory, and by the filler and adsorbed moisture. It is shown that apart from relaxation transitions and phase transitions associated with glass transition, crystallization and melting (whose particular features will depend on thermal prehistory and on filler concentrations) transitions due to the presence of adsorbed moisture may occur in filled organosilicon rubbers. Transitions have been detected and interpreted in terms of the mobility of macromolecules in the polymer-filler transitional zone, release of the mobility of molecules of condensed water and high temperature desorption of H 2 O.