碳—碳键新型引发剂的研究

STUDIES ON NEW TYPE CARBON-CARBON BOND INITIATORS

α-氰基苯乙酸乙酯用Cu^(++)-TMEDA-O_(2)进行氧化偶联反应,产物经色谱或重结晶法分离,经红外光谱、紫外光谱、^(1)H核磁共振谱、质谱、元素分析鉴定及其碱性水解产物等认定为内消旋-2,3-二氰基-2,3-二苯基丁二酸二乙酯(Ⅰ).用Ⅰ引发苯乙烯进行本体聚合,测定了聚合温度和Ⅰ的用量对苯乙烯的转化率~时间曲线的影响,测定了各种条件下所得聚苯乙烯的分子量及其分散系数.1是一种既有效又安全的碳—碳键型引发剂.

Diethyl 2,3-dicyano-2,3-diphenylsuccinate(I)was synthesized by oxidative coupling"reaction of ethyl a-cyanophenylacetate with Cu^(++)-TMEDA-O_(3)system.The structure of I is determined on the basis of IR,1HNMR,UV,MS and elemental analysis,and through alkaline hydrolysis of I to 2,3-diphenylsuccinonitrite.The configuration of I is identified to be the meso-isomer by x-ray crystallographic analysis in collaboration with the Institute of Physical Chemistry of Beijing University.The conversion-time curves are determined when I was used as initiator in the bulk polymerization of styrene at 80,90,100,110 and 120℃respectively.Mw,Mn and dispersion coefficients of polymers obtained with a fixed amount of I as initiator in the bulk polymerization of styrene at 70,80,90,100,110,120 and 150℃or with various amounts of I as initiator at 100℃are determined by GPC.The results show that I is a safe and efficient carbon-carbon bond initiator.