Study on Hydrosilylation of Acetylene and Methyldichlorosilane II.Effect of Mode of Reactant Feeding and Protective Agent of Catalyst

he effect of mode of reactant feeding on hydrosilylation of acetylene and methyldichlorosilane was studied. Three modes of reactant feeding were applied to study the effect. Influence of reaction conditions such as temperature, solvent and flow rate of acetylene on hydrosilylation under various modes of reactant feeding were also investigated. Results showed that under various modes of reactant feeding, conversion of SiH and selectivity for the first addition product were markedly different, and the effect of reaction conditions on hydrosilylation were also very different. The optimal mode of reactant feeding and reaction conditions were obtained. Polymethylvinylsiloxane is synthesized from the hydrolytic polycondensation reaction of methylvinyldichlorosilane. With polysiloxane as the protective agent, the colloidal platinum is prepared by the thermal decomposition of chloroplatinic acid in xylene solvent at 383 K. Results showed that the colloidal platinum is stable and active for the hydrosilylation.