Synthesis and characterization of high molecular weight atactic polybutene-1 with a monotitanocene/methylaluminoxane catalyst system

摘要

A novel catalyst precursor,the monotitanocene (#eta#~5-pentamethylcyalopentadienyl)titanium tricinnamyloxide [Cp*Ti(OCH_2-CH=CHC_6H_5)_3],was synthesized and employed for butene-1 polymerization in the presence of methylaluminoxane.The effects of the polymerization conditions on the catalytic activity,molecular weight,stereoregularity,and regioregularity of the polymer so obtained were investigated in detail.The results show that the monotitanocene is desirable for the production of atactic polybutene-1 coupled wiht good yields under typical polymerization conditions,high molecular weihgt (weight-average molecualr weitht=5.3-9.6*10~5),and stereoirregularity with the Bernoullian factor B equal to 0.95,which indicates that chain-end control is predominant.