笼型八乙烯基POSS改性EPDM的热稳定性

Properties of EPDM rubber modified by octavinyl silsequioxane

采用红外光谱(FTIR)和热分析(TG)方法研究不同用量八乙烯基多面体低聚倍半硅氧烷(POSS)改性三元乙丙橡胶(EPDM)化学反应,并初步探讨了其反应机理。结果表明,经高温硫化可以实现八乙烯基POSS在EPDM橡胶上的接枝,且用量越高,接枝率越高;随着八乙烯基POSS用量的增加,POSS/EPDM热稳定性升高。与理论质量损失率相比,POSS/EPDM实际质量损失明显降低,且随着POSS用量的增加,两者相差越大;其改性机理为八乙烯基POSS上的乙烯基,在过氧化二异丙苯(DCP)热引发剂存在条件下,经高温将其以化学键合的方式连接到EPDM链上,实现POSS对EPDM橡胶的改性。

Infrared spectroscopy and thermal analysis were used to study the chemical reactions of different amounts of octavinyl silsequioxane POSS modifying EPDM rubber,and the reaction mechanism was preliminary speculated.The results showed that the grafting of octavinyl silsequioxane on EPDM rubber could be achieved by high temperature vulcanization.The higher the dosage,the higher the grafting rate.With the increase of octavinyl silsequioxane dosage,the thermal stability of POSS/EPDM increases.Compared with the theoretical weight loss rate,the actual weight loss rate of POSS/EPDM is significantly lower,and as the amount of the POSS increase,the difference between the two is greater.It is speculated that the modification mechanism may be that the vinyl group on POSS is chemically bonded to the EPDM molecular chain by being heated at a high temperature in the presence of a DCP thermal initiator to realize the modification of EPDM rubber by POSS.