【摘要】 本文采用交叉分级法和体积排斥色谱法(SEC)分别测定了聚对苯二甲酸乙二醇酯-聚四亚甲基醚多嵌段共聚物(PET-PTMG)的分子量分布和组成分布,并对两种方法的结果进行了比较。讨论了PET-PTMG的交叉分级和体积排斥色谱规律。结果表明:当共聚物的各组成相容性很差时(例如PET-PTMG),交叉分级对组成分离起主要作用,而对分子量分离的效率较差;由SEC法测定共聚物的组成分布只是反映组成随分子量变化的情况,而不能代表真实的组成分布;PET-PTMG～氯仿体系并不符合SEC普适校正规律。更多还原

【Abstract】 Poly（ethylene terephthalate）-Poly （tetramethylene ether） multiblock copolymersample was fractionated by cross fractionation using two different solvent/nonsolventsystems. Eighteen fractions with different molecular weights and different chemicalcompositions were obtained. These fractions were employed to study the solutionproperties and characteristics of PET-PTMG copolymer. The composition distribution and molecular weight distribution were constructedfrom the cross fractionation data and SEC measurement. The comparison between theresults of two methods have been made. The behaviours of cross fractionation and SECof PET-PTMG have been discussed. The findings are as follows: 1. Cross fractionation trends to separation according to composition for the copo-lymer with highly incompatibility of components and can not deduce the true molecularweight distribution. 2. SEC determination gives only information on the composition drift as functionof apparent molecular weight but not the true composition distribution. 3. The SEC universal calibration method is not applicable for PET-PTMG multi-block copolymer in CHCl₃.更多还原