聚氯乙烯与丁腈橡胶交联反应的分子模拟

用分子模拟方法对聚氯乙烯(PVC)与丁腈橡胶(NBR)化学交联机理及交联反应位置进行了研究,通过DMol 3计算反应的自由能、活化能和反应热,进而研究他们对交联反应行为的影响。模拟结果显示:在453K时,过氧化二异丙苯(DCP)能够引发NBR发生夺取α-亚甲基活泼氢的反应和双键的加成反应,产生NBR大分子自由基,进而引发NBR的自交联反应,加成反应的速率要快于夺取α-亚甲基活泼氢的反应速率;DCP能够引发PVC发生脱氢反应,形成PVC大分子自由基进而引发PVC的交联,但不能引发PVC发生脱氯的反应;PVC与NBR能够发生共交联反应;NBR的自交联反应最快,PVC与NBR的共交联反应次之,PVC的自交联反应最慢。

Molecular Simulation on Cross-linking Reaction of PVC/NBR

Cross-linking mechanism and cross-linking position of polyvinyl chloride(PVC)/nitrile butadiene rubber(NBR) blends were studied using molecular simulation method.Cross-linking behavior of PVC/NBR blends was studied using the free energy,activation energy and heat of reaction,which were calculated by DMol3.Computer simulation results show that through dicumyl peroxide(DCP) initiator,macromolecular radical of NBR are produced by capturing α-methylene hydrogen and double bond addition reaction,which initiates self-cross-linking reaction of NBR.The rate of addition reaction is higher than that of capturing α-methylene hydrogen reaction.DCP can initiate dehydrogenation of PVC chain to produce PVC chain radical to further intiate self-cross-linking reaction,but it cannot produce dechlorinate reaction.PVC and NBR can produce co-cross-linking reaction.The rate of co-cross-linking reaction of NBR and PVC is higher than that of PVC self-cross-linking reaction,and slower than that of NBR self-cross-linking reaction.