摘要
通过傅里叶红外光谱仪(FTIR)、扫描电镜(SEM)及电化学测试等技术,研究了环氧涂层在不同大气环境中的老化规律及涂层物理性能、腐蚀防护性能的演变。其中环境1与环境2纬度、平均温度基本相同,环境1的光照强度高于环境2,湿度低于环境2。研究表明:涂层失光率与黄色指数随光照时间的增加而显著增大。涂层接触角、附着力随光照时间的增加呈下降趋势。光照12个月后发生明显变化,环境1与环境2环氧涂层的接触角由初始的75.2°分别下降到40.5°和38.3°,附着力由最初的1.7 MPa分别降低到0.3 MPa与0.2 MPa。随着光照时间的延长,涂层老化降解明显,表面出现显微缺陷,涂层的保护性能降低。光照时间超过5个月后,环境1与环境2中环氧涂层电化学阻抗谱都表现出两个时间常数的特征,说明涂层开始失去保护性能。
The aging phenomenon,the evolutions of corrosion protection performance and physical properties were investigated on epoxy coatings by Fourier infrared spectrometer(FTIR),scanning electron microscopy(SEM)and electrochemical tests in different atmospheric environments.The latitude and average temperature of environment 1 and environment 2 were basically the same,the illumination intensity of environment 1 was higher than that of environment 2,and the humidity was lower than that of environment 2.The results showed that the light loss rate and yellow index of the coating increased significantly with the increase of light duration.The values of contact angle and coating adhesive force declined with the increase of illumination time.After 12 months exposure test,the contact angle of epoxy coating in environments 1 and 2 changed from the initial 75.2°to 40.5°and 38.3°,and the adhesive force changed from 1.7 MPa to 0.3 MPa and 0.2 MPa,respectively.As the illumination time extended,the coating aging degradation was significant,which presented that some microscopic surface imperfections occurred and the protective performance of the coating decreased.After the exposure time exceeded five months,the electrochemical impedance spectra of the epoxy coatings in both environment 1 and environment 2 showed two time constants,indicating that the coatings began to lose their protective properties.
作者
颜晨曦
曹建平
于洋
YAN Chenxi;CAO Jianping;YU Yang(Shougang Research Institute of Technology,Beijing 100043,China;Key Laboratory for Corrosion and Protection,University of Science and Technology Beijing,Beijing 100083,China)
出处
《电镀与精饰》
CAS
北大核心
2021年第6期50-56,共7页
Plating & Finishing
基金
国家重点研发计划项目(2016YFC0401205)。
关键词
环氧涂层
老化行为
接触角
防护性能
epoxy coating
aging behavior
contact angle
protective property
