The Research On Synthesis Of APEG-based Polymer By Light Catalytic Synthesis

Nowdays, the application of TiO2in Photo-catalytic area mainly included degradation of organic pollutants, oxidation-reduction reaction et al. Some researchers used photo-catalyst synthetize organic compounds such as carbonylation, olefins oxidation, polymerization et al.Generally speaking, polymerization was the single and monomeric, heterogeneous catalytic reaction in an organic solvent and the yield rate was law. To deal with these problems in photo-catalytic polymerization, we used impregnation method to modify photo-catalyst and added of H2O2to catalysis polymerization synergistically. The process unproved the yield rate of the reaction and achieved terpolymer in chains and larger molecular weight.In this study, TiO2and TiO2/SiO2nanoparticles were prepared and modified, terpolymer was obtained by the photo-catalytic copolymerization of APEG and small monomer using the modified nanoparticles.Compared with TiO2, specific surface areas of complex catalyst TiO2/SiO2had been improved to a large extent. It was good for the contact with reactant and photo-catalyst. The process of non-toxic and pollution-free is a kind of new method for synthesis of polycarboxylate superplasticizer.Firstly, various rations of complex catalyst TiO2/SiO2was prepared by sol-gel method with tetraethoxysilane as silicon source and tetrabutyltitanate as a precursor.The complex catalyst TiO2/SiO2were characterized with X-ray crystal diffraction, N2physical adsorption, infrared spectroscopy.The results indicated that anatase with Ti-O-Ti exited in the complex catalyst TiO2/SiO2and the addition of SiO2increased specific surface areas of complex catalyst TiO2/SiO2. The photocatalytic activities of the different samples were measured by the degradation of rhodamine B(RhB) in an aqueous solution.The results showed TiO2/SiO2calcinated at550℃have the best photo-catalytic properties.Secondly, Different amount of modified TiO2nanoparticles were used to initiate the polymerization of APEG, MA and monomethyl maleate under high pressure Hg lamp. In this study, the amounts of modified TiO2nano-particles and H2O2and the time of light were investigated.The result manifested that reaction conversion rate is highest to74.29%when the amounts of modified TiO2nanoparticles and6%and1.5ml respectively and the time of light was4h.At last, the modified complex catalyst TiO2/SiO2was studied to initiate the polymerization of APEG, MA and monomethyl maleate.The influence of modified TiO2and TiO2/SiO2nanoparticles to reaction conversion rate were compared Modified TiO2/SiO2showed high catalytic efficiency.