具树状支化特征的高分子构筑单元及其聚合行为

DENDRITIC BUILDING BLOCKS AND THEIR BEHAVIOR OF POLYMERIZATION

合成了两种具树状支化特征的新化合物，这些楔形分子的弧形端围有多个羟基而顶端带双键，成为可聚合单体．同时研究了这类楔形分子在自由基引发体系中的聚合行为，结果表明，这些单体与一般烯丙基类单体的聚合行为一致，楔形分子的多个羟基及其分布基本不影响烯基的聚合活性．顶端为烯丙基醚的树状单体可与丙烯腈等带吸电子基团的单体共聚，但不能进行均聚；而顶端为甲基丙烯酸酯的树状单体均聚及与丙烯腈共聚的反应都可以顺利进行．这类多羟基的楔形分子水溶性非常好。

Two novel dendritic polymerizable monomers with multi hydroxyl groups at the arch deck and a vinyl group at the end of the wedge have been synthesized,their polymerization reactions by free radical initiation have been investigated.The results indicate that these molecules generally behave like those monomers containing allyl groups,which leads to a conclusion that the polymerization activities of the double bonds are not influenced by multiple hydroxyl groups nor their positions on the wedge.Dendron 1 with an allyl ether end can be copolymerized with electron poor olefins such as acrylonitrile,but it does not homopolymerize,Dendron 2 with an methacrylate end undergoes both homo and co polymerization rapidly.These multi hydroxyl wedges are water soluble molecules and they build a new type of polymers consisting dendritic units hanging on a flexible linear chain.Most of these polymers are also water soluble.