TMI和苯乙烯溶液共聚合的竞聚率

Monomer reactivity ratios of TMI and styrene solution copolymerization

以甲苯为溶剂和偶氮二异丁腈(AIBN)为引发剂,研究3-异丙烯基-α,α′-二甲基苄基-异氰酸酯(TMI)和苯乙烯(St)溶液共聚合的竞聚率和共聚产物(PS-co-TMI)的相对分子质量及分子质量分布.通过对共聚物产物的傅里叶红外(FTIR)分析,证实了在低转化率(<6%)下成功合成了PS-co-TMI.引入带荧光性官能团的9-(甲氨基-甲基)蒽(MAMA),通过紫外(UV)确定PS-co-TMI的组成;采用Kelen-Tudos正序和逆序法、YBR法和多元线性回归最小二乘法确定TMI(1)和St(2)的竞聚率为:r1=0.27、r2=0.91.凝胶滲透色谱(GPC)分析表明:TMI与St单体的加料量比增加,PS-co-TMI的相对分子质量和分子质量分布均减小.

In the presence of toluene as solvent and azobisisobutyronitrile （AIBN） as initiator, the monomer reactivity ratios of 3-isopropenyl-a,d-dimethylbenzyl isocyanate （TMI） and styrene （St）, and molecular weight and molecular weight distribution of as-synthesized copolymer （PS-eo-TMI） were analyzed. Fourier infrared （FTIR） analysis of as-synthesized copolymer showed that PS-co-TMI was successfully synthesized under the overall conversions less than 6 %. The copolymer composition of PS-eoTMI was determined by ultraviolet （UV） measurement with introducing 9-（methylaminomethyl） anthracene （MAMA） bearing fluorescence groups into PS-co-TMI. Using the methods of positive KelenTudos, reversed Kelen-Tudos, YBR and multiple linear regression least square, the reactivity ratios of TMI（1） and St（2） were obtained as rl ： 0.27, r2 = 0.91. Gel permeation chromatography （GPC） analysis showed that the molecular weight and molecular weight distribution of PS-co-TMI decreased with the increase of TMI/St feeding ratio.