Composite Materials with Improved Properties in Compression: AnionicPolymerization of 1-Methyl-1-Silacyclopent-3-ene. Characterization of Poly(1-Methyl-1-Sila-cis-pent-3-ene) by 1H, 13C, and 29Si NMR Spectroscopy and Mechanism of Polymerization

摘要

1-Methyl-1-silacyclopent-3-ene (I) undergoes anionic ring opening polymerizationon treatment with n-butyllithium and hexamethylphosphoramide as cocatalysts in tetrahydrofuran to yield poly(1-methyl-1-sila-cis-pent-3-ene) (II). II has been characterized by infrared and 1H, 13C and 29Si nuclear magnetic resonance spectroscopy as well as by gel permeation chromatography, thermogravimetric analysis and elemental analysis. Due to the low molecular weight of II, 1H, 13C and 29Si NMR spectroscopy affords detailed information that permits characterization of microstructures involved in initiation and termination. End groups have been identified as substituted 1-methyl-1-silacyclopent-3-enes. The mechanism of this polymerization is discussed. Anionic polymerization, Ring opening polymerization, Poly(1-methyl-1-sila-cis-pent-3-ene), Reprints, Silicon-hydride, Macromolecules. (jg)