平衡硫化体系硫化天然橡胶的平衡硫化性和化学应力松弛行为

<正>WOlff’‘,”采用双（3-三乙氧基甲硅烷基丙基）-四硫化物（St69）与硫黄组成的平衡硫化体系（EC）,既减少了硫化返原的产生,又保留了传统硫黄硫化体系（CV）的优点,同时克服了因采用有效硫化体系（EV）或半有效硫化体系（SEV）所导致的强度等

REVERSION AND CHEMICAL STRESS RELAXATION BEHAVIOUR OF NR CURED WITH EC

The reversion and chemical stress relaxation behaviour of natural rubber (NR) cured with equilibrium cure system (EC) were studied. The results manifested that the reversion and tensile strength decrease percentage of NR cured with EC after 6 hour were remarkably lower than that of NR cured with conventional vulcanization system (CV). The order of the amount of crosslinking bonds was EC>CV>SEV(semi -effective vulcanization system) during the process of chemical stress relaxation. The thermooxidative aging activation energy values of NR cured with EC, SEV and CV were 159. 5,141. 7 and 114. 6kJ/mol, and their tensile strength values were 26. 9,21. 6 and 24. 7MPa respectively. It could be inferred that one of the main reasons of lower reversion beyond 100 minute curing period was that the vul-canizate cured with EC had a good property of thermooxidative aging resistance.