将改性后的纳米TiO₂添加到聚氨酯涂料中并涂敷在A3钢电极表面，通过电化学极化曲线研究A3钢在NaCl溶液中的自腐蚀电流密度。结果表明，选用水油平衡（HLB）值为6.7的脱水山梨醇单棕榈酸酯或HLB为3.6的乙二醇脂肪酸酯表面活性剂对纳米TiO₂表面处理后，其仍具有半导体光致发光性能，并且可以在有机浆料中实现纳米级分散；添加纳米TiO₂聚氨酯涂料对A3钢电极具有明显的光电化学防腐蚀保护作用，电极自腐蚀电流密度下降1~2个数量级，最佳质量分数为1%；纳米TiO₂在自然光照和暗室条件下均可降低A3钢的自腐蚀电流密度，提高其耐腐蚀性能。

Modified nano-TiO₂ is added into polyurethane coatings,which is coated onto the surface of A3 steel electrode.Self-corrosion current density of the coated A3 steel electrode in NaCl solution is studied through electrochemical polarization curve.The experimental results show if nano-TiO₂ is treated by dehydrated sorbitan monopalmitate with a water-oil equilibrium (HLB) value of 6.7 or ethylene glycol ester surfactant with an HLB value of 3.6,it still remains semiconductor photoluminescence properties and can achieve nano-scale dispersion in organic slurry.Polyurethane coatings with modified nano-TiO₂ has obvious photoelectrochemical corrosion protection effect on A3 steel electrode,making electrode's self-corrosion current density decrease by 1-2 orders of magnitude.The best mass fraction of modified nano-TiO₂ is 1%.Modified nano-TiO₂ can reduce the self-corrosion current density of A3 steel and improve its corrosion resistance under natural light or in darkroom conditions.

姜志国(1965-),男,博士,副教授,研究方向为聚氨酯功能材料,jiangking@vip.sina.com