湿固化型石墨烯改性重防腐涂料的性能研究

Properties of Moisture Curing Graphene Modified Marine Anticorrosive Coatings

目的为延长如输电塔架等金属构件的服役期限,制备一种湿固化型石墨烯改性重防腐涂料,并测试表征和分析漆膜的防腐性能和作用机制。方法以湿气固化型聚氨酯树脂为主要成膜物,铝鳞片代替传统锌粉为主要防腐填料,石墨烯为改性剂搭配形成复合导电填料体系,借助定位排列剂等助剂制备了湿固化型石墨烯改性重防腐涂料。通过沉降测试、结合强度测试、水接触角测试、电化学测试、扫描电镜(SEM)分析、耐中性盐雾实验等手段,对涂层的常规理化性能、防腐蚀性能及微观形貌进行了表征分析,并探讨了石墨烯-铝鳞片复合填料防护体系的防腐蚀作用机理。结果定位剂有助于提高涂料的分散性和稳定性,经过石墨烯改性后,重防腐涂层的结合强度、耐盐水性、耐候性等常规理化性能明显提升,固含超过70%,达到高固含的环保要求;水接触角增至115°,涂层疏水性有效改善;中性耐盐雾试验进行1000 h时涂层划痕处有明显的腐蚀迹象,但表面未发生起泡、剥落等缺陷,单边扩蚀小于2 mm,石墨烯质量分数为0.8%的涂层性能达到最佳,耐盐雾时间达5000 h以上,此时涂层湿结合强度仍达到8.3 MPa,电化学腐蚀速率仅为0.011673 mm/a,耐腐蚀性能优异。结论石墨烯-铝鳞片复合防护体系的力学性能、机械封闭和阴极保护功能优异,属于一种底面合一的涂料,适用于湿热工业-海洋大气环境的腐蚀防护工作。

The work aims to prepare a moisture curing graphene modified marine anticorrosive coating to prolong the service life of metal components such as transmission tower and test,characterize and analyze the corrosion resistance and action mechanism of film.Moisture-curable polyurethane resin was used as film-forming material aluminum flake as conductive filler instead of traditional zine powder and graphene as a modifier to form a composite conductive filler system and prepare the moisture curing graphene modified marine anticorrosive coating with positioning agent and other additives.The conventional physicochemical properties,corrosion resistance and micro-morphology of coating were characterized and analyzed by settlement test,water contact angle,electrochemical test,scanning electron microscope(SEM)and neutral salt spray test,and its anti-corrosion mechanism of graphene-aluminum flake composite protection system was discussed.Positioning agents were conductive to improving the dispersion and stability of coatings.After graphene modification,the conventional physicochemical properties such as bonding strength,saltwater resistance,and weather resistance of the marine anticorrosive coating were significantly improved,and the solid content exceeded 70%,achieving high solid environmental protection requirements,the water contact angle increased to 115°,the hydrophobicity of the coating was effectively improved,and there were obvious signs of corrosion at the scratches of the coating when the neutral salt spray test was performed for 1000 h,but the surface did not have defects such as blistering,peeling,and unilateral corrosion less than 2 mm on one side.When the graphene content was 0.8%,the coating performance was the best,and the salt spray resistance time was more than 5000 h and the wet bonding strength of the coating still reached 8.3 MPa,the electrochemical corrosion rate was only 0.011673 mm/a,and the corrosion resistance was excellent.Graphene-aluminum flake composite protection system with excellent mechanical properties,mechanical closure and cathodic protection is a kind of bottom-in-one paint and suitable for anti-corrosion work of damp heat industries and marine atmospheric environment.