料浆法制备Na/K混合型硅酸盐涂层及其耐水性能

Water Resistance of Na/K Hybrid Silicate Coatings Prepared by Slurry Method

为了探究不同因素对硅酸盐涂层耐水性能的影响程度,以Na_2SiO_3和K2SiO_3混合溶液为基料,以氟硅酸钠(Na_2SiF_6)为固化剂,采用料浆法在304不锈钢基体表面喷涂制备了Na/K混合型硅酸盐涂层。以耐水时间和吸水率作为评判指标,分别研究了基料体系、Na_2SiF_6质量分数和固化温度对涂层耐水性能的影响机理,使用扫描电子显微镜(SEM)对涂层的微观形貌进行表征。结果表明:基料质量分数对涂层耐水性能的影响程度最大,其次为Na_2SiF_6质量分数和固化温度;提高硅酸盐涂层耐水性能的关键在于促进硅酸凝胶,形成硅氧键相互交联的网络结构;基料质量分数为30%,Na_2SiF_6质量分数为2%,固化温度为80℃时,所制备的硅酸盐涂层吸水率为6.8%,表现出优异的耐水性能。

To explore the affecting degree of different factors to silicate coatings’water resistance,Na/K hybrid silicate coatings on 304 stainless steel matrix were sprayed in a slurry method,while the binder was mixed with sodium silicate and potassium silicate solution,sodium fluorosilicate served as curing agent.It discussed the affecting regular of silicate binder system,sodium fluorosilicate mass fraction,curing temperature to coatings’water resistance according to water absorption rate and water resistant time;the microscopic morphology was also characterized by scanning electron microscopy(SEM).The results show that binder system plays the most important role in affecting coatings’water resistance,followed by the curing agent mass fraction and curing temperature.The key to improving the water resistance of silicate coatings is to promote the silicic acid gel,forming a network structure in which the siloxane bonds are cross-linked.When binder mass fraction is 30%,sodium fluorosilicate mass fraction is 2%,curing temperature is 80℃,the water absorption rate of coatings is 6.8%,the coating behaves perfect water resistance.