多官能团单体对聚乙烯的增感辐致凝胶效应  

Radiation-Induced Gel Effect of Polyethylene Sensitized by Polyfunctional Monomer

作　　者：刘飞跃[1] 张丽叶[2] 

机构地区：[1]中国科学院广州化学研究所,广东广州510650 [2]北京化工大学材料科学与工程学院,北京100029

出　　处：《中国塑料》2002年第7期29-36,共8页China Plastics

摘　　要：研究了典型的多官能团单体三羟甲基丙烷三甲基丙烯酸酯 (TMPTMA )对不同种类聚乙烯辐致凝胶效应的促进作用。实验表明 :多官能团单体对聚乙烯早期的辐射交联有显著的促进作用 ,但随着剂量的增加 ,作用逐渐减弱直至消失。它对聚乙烯的极限凝胶分量几乎没有贡献。这种作用对聚乙烯的品种没有选择性。依据对实验事实的分析 ,多官能团单体对聚乙烯辐射交联的促进机理应是 :辐射引发单体聚合 ,在聚合的同时向大分子链频繁发生链转移 ,从而形成大分子 -单体聚合物之间的交联网络。由于更高的剂量率能够引发更多的聚合反应动力学链 。The influence of typical polyfunctional monomer, trimethylolpropane trimethacrylate (TMPTMA), on radiation induced crosslinking of several kinds of polyethylene was investigated. The presence of polyfunctional monomer can evidently promote crosslinking of polyethylene without regard to its kind or grade when dose is not high. The promotion of monomer decreases with dose increasing and fades away finally. The presence of monomer is almost no contribution to ultimate gel fraction of polyethylene. The mechanism of sensitized radiation crosslinking is supposed that radiation initiates the polymerization of polyfunctional monomer at first, during which free radical transfers to macromolecule frequently and macromolecule radical will initiate another polymerization of monomer. Thus network is formed between macromolecule and polymerized monomer. Higher dose rate initiates more kinetic chains and more chain transformations. So higher dose rate can help monomer to sensitize radiation crosslinking of polyethylene.

关 键 词：多官能团单体 聚乙烯 增感辐致凝胶效应 辐射 交联 

分 类 号：TQ325[化学工程—合成树脂塑料工业]