不同结构Iniferter引发苯乙烯聚合反应的研究

The Radical Polymerization of Styrene Initiated by Different Iniferter

以不同结构的含氯化合物与铜试剂反应合成了4种链引发-转移-终止剂(Iniferter)。研究了它们引发苯乙烯的聚合反应过程,重点考察了Iniferter结构对聚合产物的影响。采用核磁共振氢谱和凝胶渗透色谱对聚合物分子量和分子量分布进行了测定。结果表明:Iniferter结构对聚合反应速率、分子量实测值与理论值间的对应关系及分子量分布均有明显影响,当其形成的初级自由基上带有使其稳定的基团时,引发效率就高,聚合反应速率较快,而且分子量理论值与实测值两者更接近。加入四甲基秋兰姆化二硫组成双组份Iniferter引发体系可以在一定程度上使聚合物分子量分布变窄。

Four kinds of iniferter with different structure were prepared and used to initiate the polymerization of styrene under U.V. light. It was shown that the polymerization rate, the correlation between theoretical molecular weight( n.th ) and founded molecular weight( n.GPC ) as well as molecular weight distribution(MWD) were affected by the initiator structure. For initiator with stabilization effect, such as MADC, the initiation efficiency is higher, so the polymerization rate is faster and the correlation between n.th and n.GPC is also better, but the MWD is too wide to meet the criterion of living polymerization. The introduction of TMTD to the initiator system to form a double component iniferter system can improve the correlation between n.th and n.GPC as well as MWD relatively accompanied with some decrease of polymerization rate.