以甲基三甲氧基硅烷为粘结剂的无铬锌铝涂层的制备及性能

Preparation and properties of chromium-free zinc flake coating with methyltrimethoxysilane as binder

制备了一种以甲基三甲氧基硅烷(MTMS)作为粘结剂的无铬锌铝涂层,其烧结温度为230°C,比采用KH560硅烷偶联剂制备的略低。通过动电位极化曲线测量及5%Na Cl溶液浸泡试验,比较了不同含水量的MTMS水解液所制锌铝涂层的耐腐蚀性能,结果表明,含水40%的MTMS水解液所制涂层具有更好的耐蚀性。分别采用红外光谱和X射线衍射分析了涂层粘结剂的成膜状况及涂层烧结后的表面氧化情况。结果表明,在230°C时下能有效成膜,且涂层表面的锌、铝粉体无严重氧化。

A chromium-free zinc flake coating was prepared with methyltrimethoxysilane （MTMS） as binder by sintering at 230 ℃ which is slightly lower than the sintering temperature of the coating made with KH-560 silane coupling agent. The corrosion resistance of the coatings prepared using the MTMS hydrolysate with different water contents was compared by potentiodynamic polarization curve measurement and immersion test in 5% NaC1 solution. The results showed that the coating prepared using a MTMS hydrolysate which contains 40% of water has the optimal corrosion resistance. The film formation of the binder and the oxidation of the coating surface after sintering were analyzed by infrared spectrometry and X-ray diffraction. The results indicated that the coating can be formed effectively at 230 ℃ and no severe oxidation is found for zinc and aluminum flakes on its surface.