Abstract
With a view to improve degradation properties of natural rubber on prolonged cure at moderately high temperature, a study is made using a co- vulcanizable processing aid known as trans-polyoctenylene (TOR) on natural rubber filled compounds. Rheometer results show that reversion resistance im proves at all curing temperatures in the presence of TOR-more so with EV (efficient vulcanization) and semi-EV systems compared to CV (conventional vulcanization) systems. Cure rate diminishes and activation energy increases with incorporation of TOR in natural rubber irrespective of the curing system. Modulus and hardness retention also are much better for TOR filled com pounds under anaerobic conditions. Tensile strength, however, drops unlike modulus and hardness. Heat buildup and loss tangent (tanδ) results reveal less heat development in TOR filled compounds. Retention of Vr (volume fraction of rubber) value indicates a similar trend like modulus and hardness, showing preservation of network structure. Such an improvement of reversion prop erties under anaerobic ageing conditions may be attributed to simultaneous crosslink formation on TOR phase in addition to natural rubber phase which has been explained through DSC studies.
Get full access to this article
View all access options for this article.