TY - JOUR
T1 - Renewable chain transfer agents for metallocene polymerizations
T2 - The effects of chiral monoterpenes on the polyolefin molecular weight and isotacticity
AU - Mathers, Robert T.
AU - Damodaran, Krishnan
PY - 2007/8/1
Y1 - 2007/8/1
N2 - 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.
AB - 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.
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U2 - 10.1002/pola.22111
DO - 10.1002/pola.22111
M3 - Article
AN - SCOPUS:34547676264
SN - 0887-624X
VL - 45
SP - 3150
EP - 3165
JO - Journal of Polymer Science, Part A: Polymer Chemistry
JF - Journal of Polymer Science, Part A: Polymer Chemistry
IS - 15
ER -