Renewable chain transfer agents for metallocene polymerizations: The effects of chiral monoterpenes on the polyolefin molecular weight and isotacticity

Robert T. Mathers, Krishnan Damodaran

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

Monoterpenes were used as renewable chain transfer agents and polymerization solvents for metallocene/methylaluminoxane (MAO) catalysis. The polymerization of 1-hexene, ethylene, and propylene in ¿-limonene, hydrogenated d-limonene and α-pinene is reported. As detected by 1H NMR analysis of the alkene region, chain transfer to d-limonene yielded a higher percentage of trisubstituted alkenes. Size exclusion chromatography detected a decrease in molecular weight values resulting from chain transfer to d-limonene. The [mmmm] pentads for isotactic polypropylene were characterized by 13C NMR and FTIR spectroscopy. Propylene polymerizations with the Et(Ind) 2ZrCl 2/MAO and Me 2Si(Ind) 2ZrCl 2/MAO catalyst systems in d-limonene gave [mmmm] pentad values as high as 0.97. For the Et(Ind) 2ZrCl 2/MAO catalyst system at 0 °C, the mol fraction of [mmmm] pentads increased from 0.86 to 0.94 upon switching the solvent from toluene to d-limonene.

Original languageEnglish (US)
Pages (from-to)3150-3165
Number of pages16
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Volume45
Issue number15
DOIs
StatePublished - Aug 1 2007

All Science Journal Classification (ASJC) codes

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry

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