TSDC study of chemical induced crosslinking in polybutadiene rubber

The thermally stimulated depolarization currents (TDSC) method was used as a tool to monitor and analyze the complex relaxations occurring in pristine and in crosslinked butadiene polymers. A TSDC peak was observed in the range 180-205 K,which can be ascribed to the relaxation at the /spl alpha/ (or glass-rubber) transition, detected also by complementary mechanical and calorimetric measurements The relaxations are due to the cooperative motions of the chain segments in the amorphous network phase. The position, width, and area (i.e. polarization) of the observed TSDC peaks depend on the crosslink density (in the range 500/spl divide/3000 mol m/sup -3/).