A novel SiO₂-supported inorganic and organic hybrid chromium-based catalyst for ethylene polymerization

详细信息	查看全文 | 推荐本文 |

• 作者：Shiliang Zhang^a ; Qi Dong^a ; Ruihua Cheng^a ; Xuelian He^a ; ^{hexl@ecust.edu.cn} ; Quntao Wang^b ; Yan Tang^b ; Yongling Yu^b ; Kan Xie^b ; Jianwen Da^b ; Boping Liu^a ; ^{boping@ecust.edu.cn}
• 关键词：Phillips CrOx/SiO2 catalyst ; S-2 catalyst ; Inorganic and organic hybrid chromium-based catalyst ; Ethylene polymerization
• 刊名：Journal of Molecular Catalysis A ; Chemical
• 出版年：2012
• 期刊代码：57_13811169
• 类别：ch
• 出版时间：June, 2012
• 卷：358
• 期：Complete
• 页码：10-22
• 文件大小：547 K

摘要

In this work, a novel SiO₂-supported hybrid chromium-based catalyst for ethylene and ethylene/1-hexene polymerization was prepared by using the residual surface hydroxyl groups in Phillips catalyst to further support bis(triphenysilyl) chromate (BC) in order to get the merits from two important chromium-based catalysts namely inorganic Phillips and organic S-2 catalysts. By characterization of the catalysts, investigation of the polymerization behavior and the microstructures of polymers, several vital factors such as cocatalyst, the addition amount of BC, calcination temperature, total chromium loading, polymerization temperature, pressure and hydrogen were systematically investigated. The proper addition weight amount of BC was Cr_BC 鈮?#xA0;0.25 wt%. The suitable calcination temperature and total chromium loading were 鈮?00 掳C and 鈮?.5 wt%, respectively. With increasing the relative addition amount of Cr_BC from 0 to 20, 50, 80 and 100 wt%(corresponding from Phillips to HCat-1, HCat-2, HCat-3 and S-2 catalysts), the copolymerization abilities of the above catalysts showed a decreasing tendency. By comparing different chromium catalysts, HCat-2 catalyst showed higher activity than S-2 catalyst and its polymer had higher average molecular weight (MW) than that obtained from Phillips catalyst. HCat-2 catalyst got well-balanced properties mainly including activity, MW of polymers and copolymerization ability.