摘要
为了解硅氧烷水解物固化阳离子型水性丙烯酸涂料的耐腐蚀性能,使用硅氧烷水解物WKHY-601固化含叔胺基的阳离子型水性羟基丙烯酸树脂分散体制得水性金属防腐涂料,采用DSC、TGA、FT-IR和CHI660E电化学工作站等手段研究了涂料的固化机理和影响其耐盐腐蚀性的主要因素。结果表明:涂料的固化由硅羟基和树脂中的醇羟基发生反应以及硅氧烷水解物自缩合形成交联网络实现;树脂中叔胺基的含量、种类及固化剂硅氧烷水解物的用量对涂膜的耐盐腐蚀性有影响,随着叔胺基含量的增加,涂膜的自腐蚀电位升高,自腐蚀电流密度降低,叔胺基含量达到一定程度后,涂膜的自腐蚀电位和自腐蚀电流密度趋于稳定;位阻较小的二甲基型叔胺基的效果优于二乙基型的;增加硅氧烷水解物用量有利于提高涂膜的致密性,增强其耐盐腐蚀性,但用量过多时,使得涂膜中叔胺基含量降低,导致其耐盐腐蚀性减弱。叔胺基含量为0.42 mmol/g的DM型树脂与硅氧烷水解物WKHY-601按照质量比3∶1制备的涂膜样板的自腐蚀电位高达-0.298 V,自腐蚀电流密度仅为1.308×10^(-9)A/cm^(2),具有优异的耐盐腐蚀性能。
Aiming at understanding the corrosion resistance of siloxane hydrolyzate cured cationic waterborne acrylic coatings,waterborne metal anti-corrosive coatings were prepared by cationic hydroxy acrylic resin dispersion containing tertiary amine group cured by siloxane hydrolysate WKHY-601.With using DSC,TGA,FT-IR and CHI660 E electrochemical workstation,the curing mechanism of the coating and the main factors affecting its salt corrosion resistance were researched systematically.Results showed that the curing of the coating was achieved by the reaction of the silanol hydroxyl group and the alcohol hydroxyl group in the resin and the self-condensation of the siloxane hydrolyzate to form a cross-linked network.The content and type of the tertiary amine group in the resin and the amount of the curing agent siloxane hydrolyzate influenced the salt corrosion resistance of the coating film.As the content of tertiary amine groups increased,the self-corrosion potential of coating increased and the self-corrosion current density of coating declined.After reaching a certain level of the content of tertiary amine groups,the value remained stable.Besides,the dimethyl type tertiary amine group with less steric hindrance was better than the diethyl type,and the increase in the amount of siloxane hydrolyzate was beneficial to improve the compactness of the coating film and enhance its salt corrosion resistance.When the amount of siloxane hydrolyzate was excessive,the content of tertiary amine groups in the coating film would decrease,resulting in weakening the salt corrosion resistance.Furthermore,the self-corrosion potential of the coating sample prepared by DM type resin with a tertiary amine group content of 0.42 mmol/g and siloxane hydrolysate WKHY-601 according to a mass ratio of 3∶1 was as high as-0.298 V,and the self-corrosion current density was only 1.308×10^(-9)A/cm^(2),performing excellent salt corrosion resistance.
作者
朱康
樊万鑫
宦佳琪
张晓雅
孙莺
胡和丰
ZHU Kang;FAN Wan-xin;HUAN Jia-qi;ZHANG Xiao-ya;SUN Ying;HU He-feng(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)
出处
《材料保护》
CAS
CSCD
2022年第2期54-59,共6页
Materials Protection
关键词
水性防腐涂料
阳离子型羟基丙烯酸树脂分散体
硅氧烷水解物
叔胺基
耐腐蚀性能
waterborne anti-corrosive coating
cationic hydroxy acrylic resin dispersion
siloxane hydrolyzate
tertiary amine groups
corrosion resistance performance
