马来酸酐─环氧丙烷共聚物的合成及结构表征

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF MAn-PO COPOLYMER PREPARED BY RARE EARTH COORDINATION CATALYST

本文将稀土络合物Ｎｄ（Ｐ２０４）３、Ｎｄ（Ｐ５０７）３、Ｎｄ（ｎａＰｈ）３、Ｎｄ（ａｃａｃ）３．３Ｈ２Ｏ与烷基铝组成的二元体系催化剂用于共聚马来酸酐（ＭＡｎ）与环氧丙烷（ＰＯ）获得成功．并采用１Ｈ—ＮＭＲ研究了共聚物三元组序列分布．结果表明，稀土络合催化剂为ＭＡｎ与ＰＯ共聚的优良催化刑，可得到高转化率、高交替度共聚物．共聚物数均分子量Ｍｎ和分子量分布分别为２０００—３０００、１．３—１．７，共聚物中ＭＡｎ的摩尔含量４０％以上．共聚物组成及序列分布与投料比、催化剂种类、溶剂性质等有关．理论计算表明，序列分布符合三级马尔可夫（Ｍａｒｋｏｆｆｉａｎ）过程．

ing - opening copolymerization of maleic anhydride alAn ) with propylene oxide (PO) was successfully caacced out by using rare earth complexes (i. e.,Nd (P204)3, Nd (P507)3, Nd (naph)3 and Nd(acac)3 3H2O ) in combinationwith aluminum alkyls as catalysts for the first time. The relative concentration oftriads of the MAn-PO copolylner obtained was investigated on the basis of1H-NMR in devil. The results showed that the rare earth coordination systemswere favourable catalysts for the copolymerizahon of MAn with PO, giving highyield and almost altcmating copolymer. The number-average molecular weightand molecular weight distribution were in the range of 2000 - 3000 and1. 3 - 1. 7 respodively. The composihon and the monomer distribution were affected by the monomer change ratio, the sort of catalyst, and the property of solvent.It was also found that the monomer composition of copolymer predicted from thethird - order Markoffian process fit the observed 1H - NM R data perfeCtly.