聚苯胺-氮化硼纳米颗粒复合水性环氧涂层的制备与防腐性能研究

Preparation and Anti-Corrosion Properties of Polyaniline-Boron Nitride Nanoparticle Composite Waterborne Epoxy Coating

为了提升水性环氧涂层在高盐、高湿海洋环境中的防腐性能和耐久性能,在羟基化的六方氮化硼表面通过原位聚合生长聚苯胺(PANI)得到聚苯胺/氮化硼纳米颗粒(PBN),将PBN作为防腐填料来增强水性环氧涂层的防腐性能。通过傅里叶变换红外光谱(FT-IR)和电子扫描电镜(SEM)对纳米颗粒的结构与微观形貌进行表征,采用电化学测试和中性盐雾试验(NSS)探究氮化硼、PANI改性水性环氧涂层和PBN添加量对水性环氧涂层的防腐性能的影响。结果表明:PANI在BN纳米片表面原位生长形成珊瑚状结构,向水性环氧涂层中添加0.50%(质量分数,下同)PBN后的粘结强度达到6.05 MPa,在3.5%NaCl溶液中浸泡120 h后的腐蚀电流密度(1.99×10^(-9) A/cm^(2))比纯环氧涂层(1.01×10^(-6) A/cm^(2))降低约3个数量级。这归因于添加的0.50%PBN能均匀分散在环氧树脂中,填补涂层的微小空隙并提升对腐蚀介质的阻隔作用,同时PANI具有缓蚀作用,二者协同提高纯环氧涂层的防腐性能。

For improving the anti-corrosion performance and durability of waterborne epoxy coatings in high-salt,high-humidity marine envi-ronments,polyaniline/boron nitride nanoparticles(PBN)were prepared by the in-situ polymerization of polyaniline(PANI)on the surface of hydroxylated hexagonal boron nitride(BN).In addition,PBN were used as anti-corrosion filler to enhance the anti-corrosion performance of waterborne epoxy coatings.The structure and micro-morphology of nano-particles were characterized by Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).Moreover,electrochemical tests and neutral salt spray tests(NSS)were used to explore the effects of BN,PANI modifications and PBN addition amount on the anti-corrosion performance of waterborne epoxy coatings.Results showed that PANI grew in situ on the surface of BN nanosheets to form a coral-like structure,and the bonding strength of waterborne epoxy coating reached 6.05 MPa after adding 0.50%(mass fraction,the same below)PBN.The corrosion current density(1.99×10^(-9) A/cm^(2))of the composite coating immersed in 3.5%NaCl solution after 120 h was reduced by about 3 orders of magnitude compared to that of pure epoxy coat-ing(1.01×10^(-6) A/cm^(2)).This was attributed to the fact that the addition of 0.50%PBN could evenly disperse in the epoxy resin,fill small gaps in the coating and enhance the barrier effect against corrosive medium.Meanwhile,PANI had a corrosion inhibition effect,which could synergistically improve the anti-corrosion performance of pure epoxy coatings.