摘要
稀土羧酸盐,如辛酸盐,硬酯酸盐和环烷酸盐等组成的催化体系对共轭双烯烃聚合具有良好的活性和定向效应。但体系中要有第三组分的存在,通常采用的是烷基氯化铝,其作用是与羧酸盐羧基进行交换反应,是形成活性中心的必要条件。氯化稀土组成的体系由于自身组成含有氯离子而排除了第三组分的使用,从而简化了聚合工艺流程,有利于研究体系组分之间的反应。但是并非所有氯化稀土都适宜于这种研究,原因在于大多数氯化稀土络合物不溶于惰性有机溶剂。如氯化稀土醇合物对共轭双烯烃聚合有着相当高的活性,但是研究氯化稀土醇合物与烷基铝的反应却有着一定的困难。
Theactivty of catalysts from NdCl3 ?3TBP and AlR3and Nd-Al bimetallic complex isolated from the reaction system between their components has been studied. The activities of catalysts in butadiene polymerization increase in the order AlEt3 > Al(i-Bu)3> Al(i-Bu)2H. The cis-1,4 contents of the obtained polybutadiene are 94, 98 and 98%, respectively. Under the same experimental conditions the conversion of the butadiene polymerization with the Nd-Al bimetallic complex is more than 92% at the μmol Nd/g Bd of 20, and polybutadiene still has high content of cis-1, 4 structure. The experimental results support the viewpoint that the active centre in diene stereospecific polymerization with a rare earth metal salt as main catalyst is the Nd-Al bimetallic complex.
出处
《分子催化》
EI
CAS
CSCD
1992年第1期76-80,共5页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金资助项目
关键词
络合物
氯化钕
烷基铝
丁二烯
聚合
Bimetallic complex, Neodymium chloride, Alkylaluminum, Butadiene, Polmerization
