【摘要】 90℃进行元素碘参与的甲基丙烯酸甲酯(MMA)衰减链转移聚合,发现其诱导期明显缩短,聚合速度加快,-Mw/-Mn与70℃~80℃没有明显差别。[MMA]0∶[AIBN]0∶[I2]0=1140∶1.0∶0.8时,动力学表明聚合仍具明显活性。表明普通聚合体系加少量元素碘,即可转为活性聚合。1H-NMR表明,90℃聚合时,聚合物分子结构发生变化,产生了一种新的次甲基,合理解释为Pn-I高温均裂,引发分子内重排再引发,聚合机理与70℃~80℃有所区别。更多还原

【Abstract】 Degenerative transfer radical polymerization of MMA in the presence of the element Iodine was carried out at 90 ℃,it found that induction period shortened obviously,polymerization speed accelerated and molecular weight distribution(M-w/M-n)was still lower and no significant differences with that at 70 ℃～80 ℃.When the condition was 0∶0∶0 = 1140∶1.0∶0.8 at 90 ℃,the polymerization is shown to proceed with first-order kinetics,with narrow polydispersity indices.It means that the common polymerization system is able to turn into living polymerization,while 1/1400～1800 element iodine is added into the system.The number average molecular weight is greater than theoratical one when polymerizatial temperature between 70 ℃～80 ℃,and smaller than that at 90 ℃.1H-NMR analysis of molecular structure of resulting polymer at 90 ℃ indicated a new methylene was found, the reasonable explanation is Pn-I homolysised and initiated the intramolecular rearrangement.更多还原