文献类型：期刊文献

英文题名：A Novel SiO2-Supported Cr-V Bimetallic Catalyst Making Polyethylene and Ethylene/1-Hexene Copolymers with Bimodal Molecular Weight Distribution

作者：Zhao, Ning[1];Cheng, Ruihua[1];He, Xuelian[1];Liu, Zhen[1];Liu, Boping[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2014

卷号：215

期号：18

起止页码：1753

外文期刊名：MACROMOLECULAR CHEMISTRY AND PHYSICS

收录：;EI(收录号：201436013936);WOS:【SCI-EXPANDED(收录号:WOS:000342622800008)】；

基金：The authors gratefully thank the financial supports by the National Natural Science Foundation of China (nos. 21104019 and 21274040), the National High Technology Research and Development Program 863 (no. 2012AA040306). This work is also financially supported by the Fundamental Research Funds for the Central Universities, research program of Introducing Talents of Discipline of university (B08021).

语种：英文

外文关键词：copolymerization; kinetics (polym.); novel Cr-V bimetallic catalysts; short-chain branch distribution; temperature rising elution fractionation successive self- nucleation/annealing (TREF plus SSA)

摘要：A novel SiO2-supported Cr-V bimetallic catalyst for ethylene and ethylene/alpha-olefin polymerization is investigated. This catalyst is prepared using the residual surface hydroxyl groups in a SiO2-supported vanadium catalyst to support bis(triphenysilyl) chromate (BC) in order to get the merits from both the vanadium-based catalyst and the S-2 catalyst. By investigation of the polymerization behavior and the microstructures of their polymers, several vital factors, such as the addition amount of vanadium species and the dosage of 1-hexene, on the ethylene/1-hexene copolymerization are systematically investigated. The results show that the activity of each bimetallic catalyst is higher than that of the S-2 catalyst, and the product from the bimetallic catalyst shows a higher molecular weight (MW) with a bimodal molecular weight distribution (MWD). The copolymers obtained using the bimetallic catalyst also show a better short-chain branch distribution (SCBD) than that using the S-2 catalyst through a temperature rising elution fractionation (TREF) cross successive self-nucleation and annealing (SSA) characterization.