可聚合的光引发转移终止剂合成接枝共聚物

SYNTHESES OF GRAFT COPOLYMERS WITH A POLYMERIZABLE PHOTOINIFERTER

采用一种可聚合的光引发转移终止剂 ,2 N ,N 二乙基二硫代氨基甲酰氧基乙酸 β 甲基丙烯酰氧基乙酯 (MAEDCA) ,通过两种途径制备了含有聚甲基丙烯酸甲酯 (PMMA)和聚苯乙烯 (PSt)链段的接枝共聚物 .其一是将MAEDCA作为引发剂 ,在紫外光照射下引发MMA聚合 ,得到大分子单体 ,通过大分子单体与St的共聚合得到 .考察了所用大分子单体的分子量和浓度对共聚合的影响 .其二是将MAEDCA作为单体与MMA共聚得到侧链上含有N ,N 二乙基二硫代氨基甲酰氧基 (DC)基团的无规共聚物 ,P(MMA co MAEDCA) .在紫外光照射下 ,P(MMA co MAEDCA)作为大分子引发剂引发St聚合 ,得到P(MMA co MAEDCA) g PSt的共聚物 。

A polymerizable photoiniferter, beta-methaerylyoxylethyl 2-N, N-diethyldithiocarbamylacetate ( MAEDCA) was used for preparation of graft copolymers containing poly(methyl methacrylate) (PMMA) and polystyrene ( PSt) segments via two pathways. One is called the grafting-through method, which involves the synthesis of PMMA-macromonomers by using MAEDCA as a photoiniferter, and the copolymerization of the macromonomers with St initiated by conventional initiator. The effects of the molecular weight and the concentration of the macromonomers on the copolymerization behavior were studied. It shows that the lower molecular weight and the lower concentration of macromonomers were used,the higher monomer conversion and the higher molecular weight of graft copolymers were obtained. The other is called the grafting-from method, which involves the synthesis of copolymers containing pendant DC groups by copolymerization of MMA and MAEDCA initiated by AIBN,and graft copolymerization of St initiated by this copolymer under UV light irradiation. The results show that the graft copolymerization has the characteristics of living radical polymerization, and the grafted chain length can be controlled by the monomer