共价功能化POSS/PDMS防腐复合涂层的研究

Research on covalent functionalized POSS/PDMS anticorrosive composite coating

首先采用硅烷偶联剂通过水解缩合反应方法合成氨基功能化倍半硅氧烷(POSS-NH_(2)),利用其表面氨基通过表面接枝聚合方法在倍半硅氧烷表面接枝磺化聚苯胺以实现其共价功能化,将磺化聚苯胺功能化倍半硅氧烷和聚二甲基硅氧烷通过溶液共混,利用滴涂法在Q235钢材表面制备出疏水防腐涂层。通过核磁共振(NMR)和傅里叶转换红外光谱(FT-IR)对氨基功能化倍半硅氧烷和磺化聚苯胺功能化倍半硅氧烷的结构进行表征分析;利用光电子能谱(XPS)分析磺化聚苯胺功能化倍半硅氧烷的化学组成和元素含量比例;利用扫描电子显微镜(SEM)表征磺化聚苯胺功能化倍半硅氧烷的微观形貌,观察到表面形貌较规整、呈颗粒状、纤维较粗的结构;采用静态接触角测试分析了四种涂层的疏水性,制备出的共价功能化POSS/PDMS防腐复合涂层疏水性最佳,接触角达到115°;采用EIS电化学阻抗谱和Tafel极化曲线测试表征了四种涂层的耐腐蚀性能,结果表明:共价功能化POSS/PDMS防腐复合涂层的腐蚀电位更大,腐蚀电流密度较小,由此表明所制备的材料具有优异的防腐性能。并且发现涂层的接触角越大,防腐性能越好。

Firstly,a silane coupling agent is used to synthesize amino functional silsesquioxane(POSS-NH_(2))through a hydrolysis condensation reaction method,and the surface amino group is used to graft sulfonated polyaniline on the surface of silsesquioxane by surface graft polymerization method.To achieve its covalent functionalization,the sulfonated polyaniline functionalized silsesquioxane and polydimethylsiloxane are mixed by solution,and a hydrophobic anticorrosive coating is prepared on the surface of Q235 steel by the method of drop coating.The structures of amino-functional silsesquioxane and sulfonated polyaniline-functional silsesquioxane are characterized and analyzed by nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR).The chemical composition and element content ratio of sulfonated polyaniline functionalized silsesquioxane are analyzed by photoelectron spectroscopy(XPS).The microscopic morphology of sulfonated polyaniline functionalized silsesquioxane is characterized by scanning electron microscope(SEM).Through the observation of the surface shape,the sulfonated polyaniline functionalized silsesquioxane composite has a regular appearance,granular and coarse fibers.The static contact angle test is used to analyze the hydrophobicity of the four coatings.The prepared covalently functionalized POSS/PDMS anticorrosive composite coating has the best hydrophobicity and the contact angle reaches 115°.The corrosion resistance of the four coatings is characterized by EIS electrochemical impedance spectroscopy and Tafel polarization curve test.The results show that the corrosion potential of the covalently functionalized POSS/PDMS anticorrosive composite coating is large,and the corrosion current density is small,indicating excellent corrosion resistance of the prepared material.And it is found that the larger the contact angle of the coating,the better the anti-corrosion performance.