文献类型：期刊文献

英文题名：Copolymerization of ethylene and cyclopentene with the Phillips CrO x/SiO2 catalyst in the presence of an aluminum alkyl cocatalyst

作者：Xia, Wei[1,2]; Tonosaki, Kiwamu[1]; Taniike, Toshiaki[1]; Terano, Minoru[1]; Fujitani, Tadahiro[2]; Liu, Boping[3]

机构：[1] School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan; [2] Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, Tsukuba West 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan; [3] State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai, 200237, China

年份：2009

卷号：111

期号：4

起止页码：1869

外文期刊名：Journal of Applied Polymer Science

收录：EI(收录号：20090911923112)

语种：英文

外文关键词：Ethylene - Gel permeation chromatography - Chains - Ring opening polymerization - Catalyst activity - Chromium compounds

摘要：The Phillips CrOx/SiO2 catalyst is an important industrial catalyst for ethylene polymerization. However, understanding of the state of active sites and chain propagation mechanisms concerning the Phillips catalyst is still waiting for conclusive evidence. In this work, the Phillips CrOx/SiO2 catalyst, having been calcined, was used for investigating the copolymerization of ethylene and cyclopentene in the presence of triethylaluminum as a cocatalyst for the first time. The microstructures of the polymers were investigated with 13C-NMR and gel permeation chromatography methods. Because of the absence of internal double bond (C=C) in the copolymer main chain, the ring-opening metathesis polymerization of cyclopentene was excluded during the copolymerization stage of ethylene and cyclopentene. Also, the 1,2-insertion and 1,3-insertion of cyclopentene into the polyethylene main chain were confirmed. This evidence strongly implies that Cr=C species may not be the active sites for chain propagation; instead, the Cr-C active site model under the Cossee-Arlman chain propagation mechanism may be responsible for the chain propagation during the normal polymerization period. ? 2008 Wiley Periodicals, Inc.