柠檬酸催化含环氧基硅树脂的制备及性能研究

Preparation of epoxy-containing silicone resin with citric acid as catalyst and study on its properties

以γ−缩水甘油醚氧丙基三甲氧基硅烷(GPTMS)、正硅酸乙酯(TEOS)和二乙氧基二甲基硅烷(DEDMS)为单体,柠檬酸为催化剂,三甲基甲氧基硅烷(TMMS)为封端剂,采用溶胶−凝胶法制备了含环氧基的硅树脂(ESiR)。然后以γ−氨丙基三乙氧基硅烷(KH-550)作为固化剂制得涂层。采用傅里叶交换红外光谱仪表征了ESiR的结构。讨论了制备工艺对涂层耐蚀性的影响,得到的最佳条件为:n(R)/n(Si)=0.90(其中R代表与Si直接相连的烷基),反应温度50°C,pH 4.0。所得涂层的水接触角为96.53°,干附着力为0级,湿附着力为1级,具有最小的腐蚀电流密度,最大的电化学阻抗。

An epoxy-containing silicone resin(ESiR)was synthesized by sol–gel method withγ-glycidoxypropyltrimethoxysilane(GPTMS),tetraethyl orthosilicate(TEOS),and diethoxydimethylsilane(DEDMS)as monomers,citric acid as catalyst,and trimethylmethoxysilane(TMMS)as end-capping reagent,and then mixed with 3-aminopropyltriethoxysilane(KH-550)as curing agent to form coatings.The structure of the ESiR was characterized by Fouriertransform infrared spectrometry.The effects of different preparation conditions on corrosion resistance of coatings were studied.The optimal conditions were obtained as follows:n(R)/n(Si)=0.90(R represents the alkyl directly attached to Si),reaction temperature 50°C,and pH 4.0.The coating obtained thereunder had a water contact angle of 96.53°,a dry adhesion of 0 grade,a wet adhesion of 1 grade,the smallest corrosion current density,and the largest electrochemical impedance.