Long-Chain Branches in Syndiotactic Polypropene Induced by Vinyl Chloride

✍ Scribed by Florian J. Stadler; Burçak Arikan; Joachim Kaschta; Walter Kaminsky

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 340 KB
• Volume: 211
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200900688

✦ Synopsis

Abstract

Syndiotactic polypropene was synthesized using a metallocene catalyst system and traces of VC. The use of VC was found to decrease the molar mass $\overline M _{\rm w} $ of the samples distinctly and linearly, while retaining the molar mass distribution, the crystallinity, and the syndiotacticity. The VC, however, initiates the formation of long‐chain branches, which were detected by GPC‐MALLS and rheology. Besides their effect on the viscosity and modulus functions, a thermorheologic complexity can be observed. Also the flow activation energy E~a~ was found to be increased. The modified samples did not obey the $\eta _0 /\overline M _{\rm w} $ relation for linear sPP, indicating the presence of LCBs.

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