Tetraalkoxysilanes were treated with Amberlyst 15 cation-exchange resin in hexamethyldisiloxane at 40 °C in order to substitute the trimethylsilyl group for the alkyl group in a tetraalkoxysilane partially. Tetramethoxy-, ethoxy-, propoxy-, and butoxysilanes were used for the experiments. After the treatment, SiO4R4−nXn(1≤n≤4, R=CH3, C2H5, n-C3H7, and n-C4H9, X=Si(CH3)3) were detected by gas chromatography and were identified by combined gas chromatography-mass spectrometry. The degree of trimethylsilylation of tetraalkoxysilane changed with the molar ratio of hexamethyldisiloxane to tetraalkoxysilane and quantities of the reaction products in the system depended mainly on the ratio.
用 Amberlyst 15 阳离子交换
树脂在 40 ℃ 的六甲基二
硅氧烷中处理四烷氧基
硅烷,以便用三甲基
硅基取代四烷氧基
硅烷中的部分烷基。实验中使用了四甲氧基、乙氧基、丙氧基和丁氧基
硅烷。处理后,SiO4R4-nXn(1≤n≤4,R=
CH3、
C2H5、n-
C3H7 和 n-
C4H9,X=Si( )3)通过气相色谱法检测,并通过气相色谱-质谱联用法鉴定。四烷氧基
硅烷的三甲基
硅烷化程度随六甲基二
硅氧烷与四烷氧基
硅烷的摩尔比变化,体系中反应产物的数量主要取决于摩尔比。