TMCH交联剂热分解机理研究

Study on thermal decomposition mechanism of crosslinking agent TMCH

为研究TMCH交联剂的热分解机理,采用热重⁃差示扫描量热法(TG⁃DSC)、气相色谱⁃质谱(GC⁃MS)和热重⁃红外光谱(TG⁃FTIR),分别研究1,1⁃双(叔丁基过氧基)⁃3,3,5⁃三甲基环己烷(TMCH)的热分解特性和热分解产物,再通过密度泛函理论DFT⁃B3LYP/6⁃311G+(d,p)计算,分析各个位置键断裂的难易程度,从而研究探讨TMCH的热分解历程及其分解机理。研究表明,TMCH的初始分解温度为90℃,在110~170℃下会出现快速失重热分解出大量产物;结合实验结果与理论计算推测出,TMCH的热分解机理为O—O键断裂产生叔丁基过氧基三甲基环己烷自由基和叔丁氧自由基,之后以C—O键断裂为主、C—C键断裂为辅的形式通过自由基间的再分解或相互结合产生3,3,5⁃三甲基环己酮、3,5-二甲基⁃2⁃己烯、叔丁醇、丙酮等产物。

In order to study the thermal decomposition mechanism of TMCH cross linking agent,Thermogronometric differential scanning calorimetry(TG⁃DSC)and gas chromatography mass spectrometry(GC⁃MS)and thermogray⁃infrared(TG⁃FTIR)were used to study the thermal decomposition characteristics and products of 1,1⁃bis(tert⁃butyl peroxy)⁃3,3,5⁃trimethylcyclohexane(TMCH),respectively.Decomposition mechanism of TMCH were studied and discussed by density functional theory DFT⁃B3LYP/6⁃311G+(d,p)it calculation.The research shows that the decomposition temperature of TMCH is 90℃,and a large number of products would be rapidly decomposed under 110~170℃.Combined with the experimental results and theoretical calculation,ther⁃mal decomposition mechanism of TMCH is the formation of O—O bond fracture produced tert⁃butyl peroxy⁃trimethyl⁃cyclohexane free radical.After that,C—O and C—C bond is broken as a supplement.Through the decomposition or free radicals to produce 3,3,5⁃trimethylcyclohexul,3,5⁃dimethyl⁃2⁃hexene,tert⁃butanol,acetone and other products.