Poly(propylene-g-styrene) Graft Copolymers with Well-Defined Microstructure by Metallocene Catalyzed Copolymerization of Propylene with Allyl-Terminated Polystyrene Macromonomers

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• 作者：Tam&aacute ; s Fó ; nagy ; Ulrich Schulze ; Hartmut Komber ; Dieter Voigt ; Jü ; rgen Pionteck ; Bé ; la Iv&aacute ; n
• 刊名：Macromolecules
• 出版年：2007
• 出版时间：March 6, 2007
• 年：2007
• 卷：40
• 期：5
• 页码：1401 - 1407
• 全文大小：91K
• 年卷期：v.40,no.5(March 6, 2007)
• ISSN：1520-5835

文摘

The synthesis of well-defined poly(propylene-g-styrene) (PP-g-PS) graft copolymers was investigatedby metallocene catalyzed copolymerization of propylene and allyl-terminated polystyrene macromonomer (PS-allyl) obtained via quasiliving atom transfer radical polymerization (ATRP) and subsequent carbocationic allylation.It was found that the structural parameters of PP-g-PS can be controlled in a broad range by the variation ofreaction conditions. At low conversion the number of polystyrene side chains per 1000 propylene units isproportional to the feed concentration of the PS-allyl macromonomer, while the length of polypropylene backbonedecreases with increasing feed concentration. The number-average molecular weight (M_n) of PS-allyl determinesthe side chain length, but it also affects the side chain density and backbone length. Both decrease with increasingM_n of the macromonomer. At constant pressure, by ensuring the constant concentration ratio of propylene toPS-allyl, the PP backbone length can be varied by alteration of temperature while the side chain density remainsnearly uniform. This semicombinatorial library of structural parameters vs reaction conditions affords designedsynthesis of PP-g-PS graft copolymers with predetermined structure, that is, with desired length of the PS sidechains, grafting density, and length of the PP backbone.