用单-检测器的尺寸排除色谱同时测量嵌段共聚物的组成和分子量

SIMULTANEOUS DETERMINATION OF THE COMPOSITION AND MOLECULAR WEIGHT OF BLOCK COPOLYMER BY SEC WITH A SINGLE DETECTOR

本文建议了一种使用具有单一检测器的常规尺寸排除色谱仪同时测量嵌段共聚物纽成和分子量的方法。方法要求测定原试样的特性粘数和尺寸排除色谱图,而检测器只对嵌段共聚物两个组份之中的一个有响应。首先用均聚物标样定出尺寸排除色谱柱的响应常数和分子量分离校准曲线。原试样的实验谱图用解叠方法得到共聚物和均聚物的两个组成峰。借助响应常数和普适校准原则计算得到共聚物的组成和分子量。本法应用于苯乙烯-硅氧烷嵌段共聚物的分析得到满意结果。

A method is presented for measuring the composition and molecular weight of block copolymer simultaneously by size exclusion chromatography with a single detector. The method requires intrinsic viscosity and size exclusion chromatographic data on the whole sample and that the detector be responsive only to one of the two monomer units of the block polymer. The response constant and the molecular weight separation curve are first calibrated with homo-polymer standards. The chromatogram of the whole sample is resolved into two peaks corresponding to homopolymer and block copolymer by peak resolution technique. The composition and the molecular weight of the copolymer are calculated with the aid of the response constant and universal calibration principle. The utility of the method is illustrated using a series of styrene-dimethylsiloxane block copolymer samples on a conventional SEC unit with a differential refractometer as detector.