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

Abstract

For improving the anti-corrosion performance and durability of waterborne epoxy coatings in high-salt， high-humidity marine environments， 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/cm2) 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 coating (1.01×10-6 A/cm2).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.

Keywords

• polyaniline|boron nitride|modification|waterborne epoxy coating|anti-corrosion performance