桥联茂金属催化乙烯/1-辛烯共聚合OA

In the current study,five bridged metallocene catalysts were designed and synthesized,and their structures were characterized by H nuclear magnetic resonance spectra(1H NMR)analysis.The effects of reaction temperature,reaction time,ethylene pressure,1-octene concentration,boron cocatalyst concentration,and TIBA concentration on the copolymer-ization of ethylene and 1-octene were investigated.The polymerization products were comprehensively analyzed and charac-terized using high-temperature gel permeation chromatography(GPC),differential scanning calorimetry(DSC),and nuclear magnetic resonance spectroscopy(NMR).The results indicated that the catalysts exhibited excellent thermal stability at ele-vated temperatures and superior copolymerization performance.Specifically,the catalytic activity reached 2.36×107 g/(mol·h)at 100℃,while the copolymer density was 0.875 2 g/cm3.With the increase in reaction temperature or the concen-tration of 1-octene,the catalytic activity first increased and then decreased.Meanwhile,the density of the polymerization products decreased.