聚苯胺的制备及其在压载舱涂料中的防腐性能

为满足《船舶专用海水压载舱和散货船双弦侧处所保护涂层性能标准》对压载舱涂层的防腐性能要求，开发新型聚苯胺(PANI)涂层.通过化学氧化法制备聚苯胺，并采用扫描电镜和透射电镜对其进行了形貌观察.将质量分数为5%和10%的聚苯胺添加到呋喃氧茚树脂中制备船舶压载舱防腐涂料，涂覆于Q235碳钢表面.通过附着力测试、极化曲线测试、电化学阻抗谱等表征手段，评价其力学及防腐性能，并初步探讨其防腐机理.结果表明：制备的聚苯胺有纳米纤维网状结构，有利于增加树脂的交联程度，可起到屏蔽作用；添加聚苯胺后，SEM中基体与涂层之间的界面不明显，且涂层缺陷及孔隙变少；5%PANI和10%PANI涂层的附着力分别达12.3和11.8 MPa，涂层的附着力显著提高，符合PSPC的要求；聚苯胺涂层的自腐蚀电流密度下降，自腐蚀电位正移，阻抗弧半径变大，防腐性能有了较大的提高；质量分数5%的聚苯胺涂层试样较10%试样的力学及防腐性能均有所提高，能为Q235碳钢提供更好的保护.
In order to meet the anticorrosion requirements of Performance Standard for Protective Coatings for dedicated seawater ballast tanks in all types of ships and double-side skin spaces of bulk carriers (PSPC), new polyaniline (PANI) coatings are developed. Chemical oxidation method is used to synthesize PANI. PANI is characterized by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The anticorrosion coating of ship ballast tank was prepared by adding 5% and 10%PANI to the furan resin, and coated on Q235 carbon steel. Adhesion test, polarization curve test and electrochemical impedance spectroscopy were carried out to evaluate its mechanical property and anticorrosion performance, and thus to elaborate the intrinsic mechanism. The results show that the prepared PANI has a nano-fiber network-like structure, which is beneficial to the enhanced crosslinking degree of the resin, and can play the role of shielding. After the addition of PANI, the interface between the substrate and the coating becomes unclear in the SEM images, and the coating defects and pores become less. The adhesion for 5%PANI and 10%PANI coatings significantly improved to 12.3 MPa and 11.8 MPa, respectively, which meet the requirements of PSPC. The corrosion current density decreased, the corrosion potential shifted positively, and the impedance arc increased, meaning the enhanced corrosion resistance. The mechanical properties and corrosion resistance of 5%PANI sample are better than those of the 10% sample, which can provide better protection for Q235 carbon steel.