氮丙啶交联对水性聚氨酯-丙烯酸酯力学和防腐性能的影响

Effects of Cross-Linking on the Mechanical and Anti-Corrosion Properties of Aziridine/Waterborne Polyurethane-Acrylate

通过原位聚合法得到无溶剂型聚氨酯-丙烯酸酯(PUA)复合乳液,并用氮丙啶(AZ)对其进行改性。通过红外光谱对PUA改性前后的结构进行了表征,同时研究了乳液的流变性能;通过力学性能测试、原子力显微镜测试对胶膜的性能进行表征;通过吸水率、电化学、耐盐雾等测试对涂层的防腐性进行了综合分析。结果表明,AZ能改善胶膜的力学性能,当AZ含量为7%时,胶膜的耐水性和耐溶剂性最佳,同时耐盐雾可达16d。电化学测试显示,改性后的PUA防腐涂层,腐蚀电流密度降至1.182×10-10 A/cm2。

Through in-situ polymerization,a solvent-free polyurethane-acrylate（PUA）composite emulsion was synthesized.Aziridine（AZ）/PUA was prepared by mechanical blending.The structure of PUA before and after modification was characterized by FT-IR and NMR.The effect of aziridine concentration on the rheological behavior of PUA emulsion was explored.The properties of PUA films were studied by mechanical measurement and atomic force microscopy（AFM）.The effect of AZ content on anti-corrosion property of composite coating was systematically analyzed through water absorption test,electro-chemical method and salt spray tests.The results show that AZ can greatly improve mechanical properties of PUA films,water-and solvent-resistance due to the increase of AZ content.Also the coatings are endowed with excellent anti-corrosion property after 16 dof immersion in 5% NaCI,when w（AZ）=7%.As the Tafel curves show,the corrosion current density decreases to 1.182×10-10 A/cm2.