Mathematical modelling and control of chemical composition distribution of ethylene/α-olefin copolymers made with single and combined metallocene catalysts

作     者：Soares, JBP Beigzadeh, D Duever, TA da Silva, AA 

作者机构：Univ Waterloo Dept Chem Engn Polymer Res Inst Waterloo ON N2L 3G1 Canada OPP Petroquim SA Triunfo RS Brazil 

出 版 物：《POLYMER REACTION ENGINEERING》 (聚合反应工程)

年 卷 期：2000年第8卷第3期

页      面：241-270页

核心收录：

学科分类：0817[工学-化学工程与技术] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 

主　　题：Copolymers 

摘      要：The single-site nature of metallocene catalysts permits the production of polyolefins with narrow distributions of molecular weight, chemical composition and comonomer sequence length. This enhanced control over polymer chain microstructure permits, in principle, the synthesis of polyolefins with well-controlled properties. In order to benefit from this enhanced control, one needs to understand how polymerization conditions and catalyst type affect polymer microstructure, as well as how the existing characterization techniques can be used to determine their microstructure. This manuscript investigates the effect of polymerization conditions and catalyst type on the chemical composition distribution (CCD) of ethylene/alpha-olefin copolymers made with single-site and Ziegler-Natta catalysts. Mathematical models will be used to describe CCD of polyolefins made on single- and multiple-site-type catalysts. Crystallization analysis fractionation (CRYSTAF) and temperature rising elution fractionation (TREF) are used to measure the CCD of these resins. It will be shown that the interpretation of CCDs with these mathematical models can be used to enhance our understanding on the nature of active sites present in metallocene and Ziegler-Natta catalysts.