水性聚苯胺/海泡石/丙烯酸乳液复合防腐蚀涂层研究

Waterborne Polyaniline/Sepiolite/Acrylic Emulsion Composite Anticorrosive Coating

目的研究水性聚苯胺/海泡石/丙烯酸乳液复合防腐涂层在NaCl溶液中对马口铁的防腐效果。方法采用原位化学氧化聚合方法,制备了聚苯胺/海泡石复合材料,并以丙烯酸乳液为成膜物质,制备了水性聚苯胺/海泡石/丙烯酸乳液复合防腐蚀涂层材料。通过扫描电镜和EDX对聚苯胺/海泡石复合材料的结构和形貌进行了表征。利用电化学交流阻抗谱、塔菲尔曲线和硫酸铜点滴试验,研究了海泡石/苯胺投料比、聚苯胺/海泡石复合材料用量、磷酸浓度等对复合涂层防腐性能的影响。结果扫描电镜观察显示,苯胺/海泡石复合材料具有纤维状结构。电化学测试及硫酸铜点滴试验表明,当海泡石/苯胺投料比为6:10、聚苯胺/海泡石复合材料用量为0.2%、磷酸浓度为0.1 mol/L时,其腐蚀电流密度为1.013X10^(-6)A/cm^2,腐蚀电位为-0.385V,极化电阻为14 350.8?,耐硫酸铜腐蚀时间为275 s,防腐效果最佳。结论当海泡石/苯胺投料比为6:10、聚苯胺/海泡石复合材料用量为0.2%、磷酸浓度为0.1 mol/L时,水性聚苯胺/海泡石/丙烯酸乳液复合防腐涂层对马口铁具有最佳的防腐效果。

The work aims to study anti-corrosion effects of waterborne polyaniline/sepiolite/acrylic emulsion composite coatings on tinplate in sodium chloride medium.Waterborne polyaniline/sepiolite/acrylic emulsion composite anti-corrosive coating was prepared by blending polyaniline/sepiolite composite synthesized in the method of in-situ chemical oxidization po-lymerization with acrylic emulsion as film-forming material. Structure and morphology of the polyaniline/sepiolite composite were characterized using scanning electron microscopy and EDX. Effects of sepiolite/aniline feed ratio, polyaniline/sepiolite composite consumption and phosphoric acid concentration on corrosion resistance of composite coating were studied using electrochemical impedance-spectra, Tafel curve and copper sulfate dripping test.SEM indicated that polyaniline/sepiolite com-posite had fibrous structure. Electrochemical test and copper sulfate dripping test showed that polyaniline/sepiolite/acrylic emul-sion composite coating exhibited the best anticorrosive performance. Provided with sepiolite/aniline feed ratio of 6：10, polyani-line/sepiolite composite consumption of 0.2% and phosphoric acid concentration of 0.1 mol/L, the corrosion current was 1.013×10-6A/cm2, corrosion potential was -0.385 V and polarization resistance was 14350.8？. Polyaniline/sepiolite/acrylic emulsion composite coating has the best anti-corrosion effect on tinplate provided with sepiolite/aniline feed ratio of 6：10, po-lyaniline/ sepiolite composite consumption of 0.2% and phosphoric acid concentration of 0.1 mol/L.