2-(N,N-二乙基二硫代氨基甲酰氧基)乙酸苄酯存在下苯乙烯光聚合

PHOTOPOLYMERIZ ATION OF STYRENE WITH BENZYL N, N- DIETHYLDITHIOCARBA MYLACETATE

研究了２ Ｎ， Ｎ二乙基二硫代氨基甲酰氧基乙酸苄酯（ Ｂｚ Ｄ Ｃ Ａ） 引发的苯乙烯光聚合反应，发现单体转化率和数均分子量（ Ｍｎ） 都随反应时间而增加，在反应时间相同时随着 Ｂｚ Ｄ Ｃ Ａ 浓度的增加单体转化率升高而 Ｍｎ 降低．聚苯乙烯（ Ｐ Ｓ） 的 Ｍｎ 同单体转化率成线性关系并同理论计算值符合得较好．以２甲基２亚硝基丙烷（ Ｍ Ｎ Ｐ） 为捕捉剂用（ Ｅ Ｐ Ｒ） 技术对聚合反应机理进行了研究．认为 Ｂｚ Ｄ Ｃ Ａ 引发的 Ｓｔ 光聚合是一个“活性”

Photopolymerization of styrene ( St ) with benzyl N, N diethyldithio carbamylacetate( Bz D C A) was studied . It was found that the number average molecularweight( Mn)of polystyrene and the conversion increase with the increasing ofreaction time ,respectively. The conversion also increased with the concentration of Bz D C A,while Mndecreased with the increasing of Bz D C Aconcentration . When [ St]/[ Bz D C A] = 874 ,the Mnof P Shad alinear relationship with the conversion ,and agreed well with that calculated fromthe initial St and Bz D C A concentrations and the conversions. The mechanism of thepolymerization was proposed and the polymerization proceeded via a “living”radicalpolymerization mechanism . Under U V irradiation , Bz D C A dissociates into two kinds ofradicals:carbon Centered radical and sulfur centered radical. The primary carbon centeredradical can initiate monomer polymerization and the sulfur centered radical can reversiblyterminate with propagating radical and form a diethyldithiocarbamate( D C) end group .