ABSTRACT

Variation of surface chemical energy and its effects on adhesion strength and corrosion protection properties of epoxy coatings of mild steel substrates were studied. Results indicated that pre-treatment with a mixture of 3-glycidoxypropyltrimethoxysilane, sodium dodecylbenzene sulphonates and zinc sulphate inhibitors enhanced the corrosion protection properties of epoxy coating when compared to untreated substrates. The formation of a compact insoluble layer of zinc hydroxide/oxide together with SDBS complex on the mild steel surface was found to affect the adhesion properties and resistance towards cathodic/anodic delamination of epoxy coating. This was primarily caused by the formation of strong interfacial interaction and increased in surface passivation. The findings suggested, adhesion alone plays a little part in preventing underfilm corrosion. The underfilm corrosion activities are determined by surface passivity towards corrosion reactions.

摘要

研究了表面化学能的变化及其对低碳钢基材环氧涂层附着强度和防腐性能的影响。结果表明，与未处理的基材相比，使用 3-环氧丙氧基丙基三甲氧基硅烷、十二烷基苯磺酸钠和硫酸锌抑制剂的混合物进行预处理可增强环氧涂层的腐蚀防护性能。研究发现，在低碳钢表面上形成致密的氢氧化锌/氧化锌不溶层和 SDBS 络合物会影响环氧涂层的附着力和抗阴极/阳极分层性能。这主要是由强烈的界面相互作用的形成和表面钝化的增加引起的。研究结果表明，单独的附着力在防止膜下腐蚀方面起着很小的作用。膜下腐蚀活动由表面对腐蚀反应的钝性决定。