Author : Saeid Mehdiabadi
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (973 download)
Book Synopsis Synthesis, Characterization and Polymerization Kinetic Study of Long Chain Branched Polyolefins Made with Two Single-site Catalysts by : Saeid Mehdiabadi
Download or read book Synthesis, Characterization and Polymerization Kinetic Study of Long Chain Branched Polyolefins Made with Two Single-site Catalysts written by Saeid Mehdiabadi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in polyolefin manufacture have focused on the production of differentiated commodity polyolefins, specialty polyolefins, and polyolefins hybrids. What differentiates these new polyolefin types from commodity polyolefins is that their molecular architectures are much more complex and often contain long chain branches (LCBs), leading to unique properties that make them competitive with specialty polymers. One approach to produce these novel polyolefins is to use one or two single-site catalysts in two CSTRs in series. The first CSTR is used to make semicrystalline polymer chains, some of which must be vinyl-terminated (macromonomers). These macromonomers are then incorporated, via terminal branching, onto the chains growing in the second CSTR, becoming LCBs. If the backbone and the macromonomer have different compositions, they are called cross-products. Since it is not possible to incorporate all macromonomers, the final polymer will consist of a complex mixture of linear chains made by the two catalysts, homogeneous-branched chains (that is, chains where the backbone and all LCBs are of the same type), and cross-product macromolecules. The cross-product will add rather special properties to the polymer and, depending on its molecular architecture, the final product may act as a thermoplastic elastomer (TPE). Developing polymer reactor models for different catalyst combinations can help understand the details of these complex syntheses and to control the properties and fractions of linear chains, homogeneous-branched chains, and cross-products.