环氧氯丙烷不饱和聚酯顺-反异构化研究

Study of Cis-trans Isomerization in Epichlorohydrin Unsaturated Polyester

对环氧氯丙烷不饱和聚酯碳-碳不饱和双键的顺-反异构化进行研究。考察了KBr催化剂、温度对异构化的影响。应用核磁共振(NMR)进行分析鉴定,测定了异构化转化率。研究结果表明,KBr催化剂在135℃可促进顺-反异构化,但180℃以上对体系的异构化不起促进作用;升高温度能有效地提高聚酯分子链中顺式双键向反式双键转化的程度。异构化后的树脂具有良好的性能。

The cis-trans isomerization of C=C in epichlorohydrin unsaturated polyester was studied. The influences of catalysts(KBr) and temperature on the isomerization were explored. The extent of the cis-trans isomerization were measured by means of nuclear magnetic resonance (NMR). The results show that the presence of KBr can promote the conversion of maleate (cis) to fumarate(trans) at 135℃; however, temperatures above 180℃will have no promoting effect. Raising the temperature can also effectively increase the extent of cis-trans isornerization in the polyester molecular chain. Resins obtained after isomerization have been found to have good performances.