Abstract
In order to study temperature dependence of viscoelasticity, resilience was measured over the temperature range from -70°C to 250°C. Polybutadiene showed its Tg at -70°C, and it was partially crystallized. 1st order transition of vulcanizates occured at about 15°C. Fox′s equation could be applied to Tg of butadiene-styrene copolymers. SBR showed difference of resilience at high temperature region due to difference of polymerization condition. As for resilience near room temperature, cold SBR had superior resilience than hot, and NBR was worst, but resilience of these rubber increased gradually with rising temperature and showed almost constant maximam near 185°C. The activation energy of glass transition for SBR and NBR was 52.5 and 42.6Kcal/mol erspectively, and these glass transition were corresponded with segment motion having nearly same length as natural rubber.
