Research Of Polymerization Of Vinyl Chloride And Methyl Methacrylate With Organic Titanium Complex

Polymerization of polar monomer, vinyl chloride, catalyzed by organic titanium complexes, XTiCl3-MAO( X=CpMe5, =L0E1, (5-C5H5)Co{P(O)(OEt)2}3,=Ind) was studied. The catalyst LoaTiC3-MAO is also applied to the polymerization of methyl methacrylate. High-molecular-weight polymers are obtained by the solution polymerization with a high concentration catalyst and monomer in CH2Cl2. poly(methyl methacrylate) is obtained by bulk polymerization. The microstructure including tacticity and regio-regularities of the PVCs obtained ws investigated by 1H-NMR and 13C-NMR. The thermal properties of the PVC is studied by TGA. The tacticity of PMMA was characterized as well.For the solution polymerization of vinyl chloride under atmosphere pressure, low activity, is found for all the catalysts. As a result, high concentrations of the catalyst and monomer were applied: [Ti]= 5X10-3 mol/L, MAO/Ti=10 mol ratio, the temperature of polymerization= 20癈, time=64hours. [VC]=3.5mol/L.The polymerization of MMA was carried out by bulk polymerization with catalyst LoEtTiCl3/MAO at 50癈. The catalyst activity is not very high and polymer structure is predominantly syndiotatic.The result of the NMR of PVC indicated that the tacticity is basically the same as that obtained by radical polymerization. Some unsaturated structures originating rom are observed are few even not head-head structure which improved the thermal stability of the polymer. And it is consistent of the results of TGA.One of structural characteristics of the PVC from organic Ti complexes is that no head-head addition is observed at lower polymerization temperature, which enhance the onset temperature of thermal degradation of PVC about 50 癈,when compared with the PVC from radical polymerization.In conclusion, organic titanium complexes, were effectively in the initiation of111the polymerization of polar monomers including VC and MMA. The preliminary study in the present work shows that the polymers obtained by Ti complexes exhibit some advantages in structure and properties. The present work may be helpful for the realization of the controlled polymerization of vinyl chloride to obtain highly stereoregular and regio-regular PVC.