Ethylene-Propene Copolymerization with C1-symmetric ansa-Fluorenyl-zirconocene Catalysts: Effects of Catalyst Structure and Comonomer on Molar Mass

作     者：Simona Losio Laura Boggioni Massimiliano Cornelio Abbas Razavi Incoronata Tritto Simona Losio;Laura Boggioni;Massimiliano Cornelio;Abbas Razavi;Incoronata Tritto

作者机构：CNR–Istituto di Scienze e Tecnologie Chimiche"G.Natta"(CNR-SCITEC)via Alfonso Corti 12-20133 MilanoItaly Total Petrochemicals ResearchZone Industrielle CB-7181 FeluyBelgium 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：2020年第38卷第3期

页      面：220-230,I0005页

核心收录：

学科分类：081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：financially supported by Total. We thank G. Zannoni and D. Piovani (ISMAC) for their valuable cooperation in NMR and SEC analysis 

主　　题：Ethylene-propene Metallocene catalysts Copolymers Microstructure Molar masses 

摘      要：Ethylene-propene copolymers have been synthesized by three C1-symmetric metallocene molecules(1,2,and 3),having tert-butyl substituents on the Cp moiety,on the fluorenyl moiety,or on both moieties,and methylaluminoxane(MAO)at different polymerization temperatures and monomer *** were investigated by 13 C-NMR,1 H-NMR,and SEC analyses.A relationship was found between[EEE]/[E]ratios and copolymer molar masses in each series:the higher the[EEE]/[E]ratio,the lower the copolymer molar *** parity of[EEE]/[E]ratio,copolymer molar mass follows the order 13*** end group analysis reveals that copolymers mainly terminate when propene is the last inserted unit,confirming that it is the greater facility of Mt-P-E-poly(E-co-P)to terminate that influences the copolymer molar *** the catalysts considered,catalyst 1,which gives syndiospecific polypropene,gives greater activities,comonomer incorporation,and molar *** 3,which gives isospecific polypropene,in copolymerization performs better than 2,having the same bridge,with respect to activities,ethylene content,and molar *** good performance of this catalyst arises from the not necessity of polymer chain to back skip when ethylene is the last inserted unit.