Supported Platinum PEG Complexes Catalysts For Hydrosilylation Reaction Of Styrene And Trialkoxysilane

Hydrosilylation is one of the most important reactions in organosilicon chemistry and organic synthesis, many organic silicon compounds containing different functionsal groups have been synthesized via this reaction. So this reaction have very important industry application value. Chloroplatinic acid- isopropyl alcohol catalyst has been used widely in industry field, but two defects are obvious. First, the platinum-containing catalysts are very expensive. The recovery of catalysts is very difficult. Second, in the case of silanes with electron-donating substiuents or olefins with electron-drawing substituents, hydrosilylation with platinum catalysts is not effective. With the use of polyethylene glycol as complexant and silica as carrier, we get a very effective supported platinum complexes catalysts. In this Paper, we study the hydrosilylation which used trimethoxysilane and triethoxidesilane containing electron-donating group and styrene as crude material. The catalytic effects of supported platinum complexes catalysts for these reactons are investigated. The main results of study in this paper are summarized below:1. The catalytic properties of Silica gel supported platinum and PEG complex catalyst for hydrosilylation reaction of styrene with triethoxidesilane were studied. The effects of temperature, the the type of carrier, quantity of catalyst used on the hydrosilylation reaction were discussed. The results showed that the conversion of triethoxidesilane can reach 89% at 50℃, while the mole ratio of styrene: triethoxidesilane of 1:1, quantity of catalyst used on the hydrosilylation reaction of 0.3g (the quantity of Pt of 2.6×10^-5 mol·g-1) was chosen. The reaction of hydrosilylation has no obvious induction period.. The catalyst has a high stability, can be reused for 3 times without loss in the catalytic activity.2. The orthogonalizing design method is applied to get the optimum processing conditions for hydrosilylation of triethoxidesilane and styrene. The mole ratio of styrened and triethoxidesilane is 1:1, the reaction temperature is 70℃, quantity of catalyst used on the hydrosilylation reaction is 0.6g. We also do three parallel experiment, the result indicated conversion of triethoxidesilane can reach 91.6%.3. The catalytic properties of Silica gel supported platinum and PEG complex catalyst for hydrosilylation reaction of styrene with trimethoxysilane were studied. The effects of temperature, the mole ratio of styrened and triethoxidesilane, quantit of catalyst used on the hydrosilylation reaction, activating mode of reactant were discussed. For example: At 60℃, the effect of hydrosilylation of trimethoxysilane and styrene is best. The smaller the amount of catalyst use, the better electivity of hydrosilylation products is.