热固化对螺纹钢上硅酸钠防锈膜性能的影响

Effect of heat curing treatment on properties of sodium silicate conversion antirust coating on rebar

将螺纹钢浸入0.8 mmol/L硅酸钠水溶液中制备了防锈膜。通过电化学测试、露天耐候试验、扫描电镜、红外光谱和耐水性试验评价了常温(25°C)下自然干燥的以及经过热固化处理的防锈膜的性能,考察了固化时间对防锈膜性能的影响。结果表明:在220°C固化3.5 h后的防锈膜形成了由Si—O—Si键构成的三维网状结构,膜层均匀致密,防锈期超过2个月,耐蚀性和耐水性均好于自然干燥的防锈膜。

An antirust coating was formed on rebar by immersing in 0.8 mmol/L sodium silicate aqueous solution. The properties of the antirust coating naturally cured at room temperature （25 ℃） and the one cured by heating were studied by electrochemical measurements, outdoor weathering test, scanning electron microscopy, infrared spectroscopy and water resistance test. The effect of curing time on the properties of antirust coating was studied. The results showed that the antirust coating cured at 220 ℃ for 3.5 h, which is compact and uniform, has a three-dimensional network structure composed of Si--O-Si bond, a rust proof period of more than two months, and better corrosion resistance and water resistance, as compared with the naturally cured one.