三甲基硅基化反应的研究

本文研究了以水玻璃作为硅酸盐阴离子,按Lentz方法进行的三甲基硅基化反应。在改变反应克分子比例时,可得到不同分子量和硅基化程度的硅树脂,由此说明,在硅基化反应时可能发生聚合、解聚和水解等副反应。对影响硅树脂产率的反应条件和三甲基硅基化树脂的一些物理性质也进行了讨论。

Study on the Reaction of Trimethylsilylation of Water Glass

The Lentz's method of trimethylsilylation of water glass which is used as thesource of silicate anion has heen studied.On changing the molar ratio of reactants,we have gotthe silicon resin with different molecular weights and various degrees of trimethylsilylation.These results showed that the side reactions of polymerization,depolymerization and hydrolysisof trimethylsilyl group may be occurred during the trimethylsilylation. It has been found that the effect on the extent of trimethlsilylation by varying the reactingmolar ratio is little.The molecular weight of resin increased with decreasing the reacting molarratio of hexamethyl disiloxane.The yield of resin increased with increasing the reacting molarratio of disiloxane,the hydrolysis of trimethylsilyl group and condensation of silanol were alsoinhibited by increasing the ratio of disiloxane. The effect on the yield of resin has been studied by varying the amount of water content,when the concentration of water glass is higher than 4 moles,the formed silicic acid condensedinstantly,and the gel is formed in large quantity.The resin is obtained only in the presence ofcertain amount of water,and water content has some influence on the molecular weight and littleinfluence on the yield of resin. Some physical properties of trimethylsilyl silicon resin were reported.