用硅烯醚型引发剂进行的基团转移聚合

NEW INITIATORS FOR GROUP TRANSFER POLYMERIZATION

本文报道了一类硅烯醚型的基团转移聚合引发剂。并以负离子和HgI_2等为催化剂,进行了甲基丙烯酸酯和丙烯酸酯的基团转移聚合。得到了实测分子量和理论分子量相近且分散性较小的浆合物。进行了甲基丙烯酸甲酯的活性聚合以及其与丙烯酸酯的A-B-A型三嵌段共聚,证实具有活性高分子的特征。探讨了该类引发剂引发基团转移聚合的机理,研究了催化剂和引发剂的配合选择性以及催化剂和引发剂的摩尔比对产物分子量和转化率的影响,发现该类引发剂引发的基团转移聚合是一恒速聚合反应。

It is reported that a variety of trimethylsilyl enol ethers which are not ketene silyl acetals can be used to initiate GTP of methacrylates and acrylates. The new initiators are easy to be prepared using Et3N as catalyst from the reaction of ketones or aldehydes with Me3SiCl. PM-MA and PMA with controlled molecular weight and low polydispersity were obtained by using 1-trimethylsiloxy cyclohexene, 2-trimethylsiloxy butene-2, 2-methyl 1-trimethylsiloxy pro-pene-1 in the presence of bibenzoate, bifluoride and HgI3. The living nature of polymerization is shown by the correspondence of theoretical and observed molecular weight and the preparation of block copolymer. This initiator system provides a very useful method for the synthesis of A-B-A triblockcopolymer of MMA and BA by using GTP.