采用海水浸泡、盐雾试验、硫酸浸泡和氢氧化钠浸泡腐蚀等方法, 研究了聚脲涂层的耐腐蚀性能, 并采用扫描电镜(SEM)观察了涂层老化后的表面形貌。结果表明, 海水浸泡180天后, 聚脲涂层的拉伸强度仅下降4%, 断裂伸长率增加了1.2%。盐雾试验180天后涂层拉伸强度下降了25.7%, 断裂伸长率增加了4.2%, 涂层表面局部有孔洞, 涂层仍致密, 未影响内部结构。硫酸溶液腐蚀60天后拉伸强度降低了30%, 断裂伸长率增加了1.1%, 涂层表面产生严重的点状腐蚀, 并伴随腐蚀孔洞产生, 扩展到内部, 形成许多降解产物。在氢氧化钠溶液腐蚀条件下, 涂层拉伸强度降低了25%, 断裂伸长率增加了9.6%, 涂层表面粗糙度略有增加, 但没有影响内部结构。可见,聚脲涂层具有较好的耐海水浸泡和盐雾老化能力, 而在强酸、强碱溶液中耐蚀性略有降低。

The anti-corrosion behaviors of a polyurea coating were studied by seawater immersion, salt spray test, acid immersion and alkali immersion tests. The surface morphology of the coating was observed by scanning electron microscopy (SEM). The results indicated that the tensile strength decreased only 4% and the breaking elongation increased 1.2% when immersed in seawater for 180d. The tensile strength decreased 25.7%, the elongation increased 4.2%. and some part of the coating was corroded, but its structure remained in densification when exposed in salt fog for 180d. The tensile strength dropped 30%, the breaking elongation increased 1.1%, the surface of the coating was corroded seriously, and the corrosion was expanded to the interior, formed many degradation products, and the morphology changed severely when immersed in 10% sulfuric acid solution for 60d. The tensile strength decreased 25%, the elongation increased 9.6%, and the surface roughness increased, but internal structure was intact when immersed in 15% sodium hydroxide solution. It is suggested that the polyurea coating has good resistance to seawater immersion and salt fog corrosion, but the corrosion resistance was lowered after immersing in acid and alkali solutions.