羧酸配体对钼体系合成1,2-聚丁二烯的影响

Effect of Carboxylic Ligands on Synthesis of 1,2-Polybutadiene with Molybdenum Catalyst System

研究了MoCl_3(RCOO)_2-(i-Bu)_2AlO■CH_3(Mo-Al)催化体系在加氢汽油中合成1,2-聚丁二烯的催化行为。考察了 R 基结构、碳原子数对催化剂的溶解性、催化活性、聚合物分子量以及微观结构的影响。试验结果表明,主催化剂(Mo)中羧酸配体的静电效应对催化剂的溶解性、催化活性影响较显著,增加 Mo 上电子云密度有利于提高催化体系的反应活性;催化剂活性中心周围环境的空间位阻增大时聚合物中1,2-链节的全同立构规整度显著提高。

The catalysis of MoCl_3(RCOO)_2-(i-Bu)_2AlO-(?)(Mo-Al)in synthesizing1,2-polybutadiene with hydrogasoline as solvent was studied.Besides,the influ-ences of the group R on the solubility and the catalytic activity of the catalyst,the polymer molecular weight as well as the microstructure were also inves-tig(?)ted.Experimental results showed that electrostatic effect of carboxylic ligandsin the main-catalyst(Mo)eonsiderably influenced the catalyst solubility and cata-lytic activity,and increasing the electronic cloud density of Mo was advantageousto raising reactipn activity of the catalyst system.With increasing space impedi-ment around the active centre of the catalyst the isotacticity of 1,2-unit of poly-butadiene considerably increased.