以六氟异丙醇为溶剂的聚甲醛凝胶渗透色谱研究

The Gel Permeation Chromatography Investigation of Polyoxymethylene -hexafluoroisopropanol System

研究了均聚和共聚甲醛在六氟异内醇中的凝胶渗透色谱（ＧＰＣ）。对共聚甲醛出现的缔合现象从主链结构作了解释，并找到了避免缔合的方法；对共聚甲醛ＧＰＣ淋洗曲线上的异常小峰从聚合机理角度进行了探讨，推测得到小峰所对应的物质。确定了以六氟异丙醇为溶剂的聚甲醛的凝胶色谱表征方法，并探索采用凝胶色谱－粘度计联用法得到分子量和分子量分布结果。

The gel permeation chromatography(GPC)of polyoxymethylene(POM)-hexafluoroisopropanol(HFIP)system has been studied.The aggregation phenomenon of POM in HFIP was observed and successfully explained from the main chain structure of POM.The deaggregation can be realized by adding sodium trifluoroacetate(NaTFA)in POM-HFIP system, thus the reliable GPC chromatogram can be obtained. In the reported GPC chromatograms of POM copolymers,an abnomal small peak at higher elution volume was found but without any explanation.It was discussed in detail from polymerization mechanism of POM in this paper.The molecular weight and molecular weight distribution of POM were determined by GPC using an on-line viscosity detector.