Polymerization of vinyl chloride with butyllithiums and metallocene catalysts

Polymerizations of vinyl chloride (VC) with butyllithium (BuLi) and metallocene catalysts were investigated. In the polymerization of VC with BuLi, the activity for polymerization decreased in the following order; t-BuLi > n-BuLi > s-BuLi. A polymer controlled structurally in the main chain was found to be synthesized from the polymerization of VC with BuLi. The molecular weights of polymers obtained in bulk polymerization were higher than those of polymers obtained in solution. A linear relationship of the M-n of the polymer and the polymer yields was observed. The M-w/M-n of the polymer did not change significantly during polymerization, although the M-w/M-n was around 2. Thermal stability of the polymer obtained with BuLi was higher than that of polymer obtained with radical initiators, as determined by TGA measurements. In the polymerization of VC with Cp*TiX3/MAO (X: Cl and OCH3) catalysts, polymers were obtained with both catalysts, although the rate of polymerization was slow. The Cp*Ti(OCH3)(3)//MAO catalyst in CH2Cl2 gave higher-molecular-weight polymers in a better yield than in toluene. From elemental analysis and the NMR spectra of the polymers, the Cp*Ti(OCH3)(3)/MAO catalyst gave polymers consisting of repeating regular head-to-tail units, in contrast to the Cp*TiCl3/MAO catalyst, which gave polymers having anomalous units.