等规聚苯乙烯的分子量分级

FRACTIONATION OF ISOTACTIC POLYSTYRENE

用配位聚合法得到的高等规度的等规聚苯乙烯(i-PS),一般具有较宽的分子量分布,对其进行分子量分级是比较难的,迄今已有不少这方面的报道,其中包括采用热力学的方法,以及采用分子量降解的方法。为了获得分子量分布较窄的i-PS样品来研究单链单晶,我们也进行了i-PS的分级研究。

Fractionation of isotactic polystyrene based on phase equilibrium was preformed by using o-dimethylphthalate (DMP) as a solvent and cyclohexanol (CHA) as a nonsolvent. Fractionation with semi-preparative GPC was also preformed. The effect of fractionation based on phase equilibrium is limited, but the result obtained from semi-preparative GPC is quite well.