论文部分内容阅读
用激光小角散射光度计和激光示差折光计测定了高压法乙烯-醋酸乙烯-共聚物(EVA)在甲苯、氯化苯和邻二氯苯中的表观重均分子量_aPP、第二维利系数A2和比折光指数增量dn/dc。结果表明EVA在这三种不同溶剂中的_aPP是相等的。根据Stockmayer 以及Bushuk 和Renoit等发展的共聚物光散射理论,以上结果表明所测得的表观分子量就是EVA样品的真实重均分子量,亦表明被测定的样品有均一的化学组成,这与用共聚合动力学统计方法和化学分析法测定共聚物化学组成所得的结果一致。 用Coedhart的基团贡献公式计算了EVA在邻二氯苯中dn/dc的值,与测定值比较,两者相近。
The apparent weight average molecular weight _aPP of high pressure ethylene-vinyl acetate-copolymer (EVA) in toluene, benzene chloride and o-dichlorobenzene was measured by laser small angle scattering photometer and laser differential refractometer. The second dimension The coefficient A2 and the refractive index increment dn / dc. The results show that EVA in the three different solvents _aPP are equal. According to the light scattering theory of copolymer developed by Stockmayer and Bushuk and Renoit, the above results indicate that the measured apparent molecular weight is the true weight average molecular weight of the EVA sample, and also indicates that the sample to be measured has a uniform chemical composition, Polymerization kinetic statistical methods and chemical analysis of the copolymer obtained by the chemical composition of the results obtained. The value of dn / dc of EVA in o-dichlorobenzene was calculated using the group contribution formula of Coedhart, which was similar to the measured value.