石墨烯--锌粉长效防腐涂料的研制

Preparation of long-lasting anticorrosive graphene–zinc powder coating

在环氧富锌底漆中引入石墨烯以取代部分锌粉,制备了低锌含量(48.0%)的石墨烯-锌粉长效防腐涂料。考察了石墨烯在不同溶剂体系中的分散性,发现当混合溶剂的比例为m(N-甲基吡咯烷酮)∶m(环己酮)∶m(二甲苯)∶m(正丁醇)=50∶16∶16∶8时,石墨烯的分散较好。依据漆膜的耐中性盐雾时间和表面电阻确定了石墨烯的最佳用量为0.5%。通过与国外某品牌环氧富锌底漆进行对比,证明该涂料性能更优:不仅耐盐雾时间可达2 500 h,远长于高锌含量(80.0%)的富锌底漆的600 h,而且可直接涂装面漆,无需过渡中间层,漆膜封闭性优异,更经济环保。讨论了石墨烯在漆膜中的作用机理。

A long-lasting anticorrosive graphene-zinc powder coating with a low content （48.0%） of zinc powder was prepared by introducing graphene into the zinc-rich epoxy primer to replace part of the zinc powder. The dispersion of graphene in different solvent systems was studied, which were found to be good when the solvent is composed of N-methylpyrrolidone, cyclohexanone, xylene and n-butyl alcohol at a mass ratio of 50：16：16：8. According to the anti-neutral-salt-spray time and surface resistance of the cured film, the optimal content of graphene was determined to be 0.5%. As compared with a foreign brand＇s zinc-rich epoxy primer, this coating has better performance and is more environmentally friendly and of greater economic benefit. Not only its neutral salt spray resistance can reach 2 500 h, which is much longer than that high-zinc- content （80.0%） zinc-rich primer （600 h）, but also it can be covered directly by a matching topcoat without any intermediate coating due to its excellent sealing ability. The anticorrosive mechanism of graphene in the cured film was discussed.