Preparation of Phytic Acid/Polym-Phenylenediamine Modified Nano-SiO2 and Corrosion Resistance in Waterborne Epoxy Coatings
γ-Glycidoxypropyltrimethoxy silane(KH560)modified SiO2(f-SiO2)was prepared by sol-gel method.Polym-phenylenediamine(PmPD)prepared by in-situ polymerization of m-phenylenediamine(mPD)was covalently grafted on the surface of f-SiO2 to obtain PmPD-SiO2;finally,the combination of phytic acid(PA)and PmPD-SiO2 by intermolecular force to obtain the PA/PmPD-SiO2 composite was applied for the preparation of waterborne epoxy coatings.The structure of the products was characterized by Fourier-transformed infrared spectrum,thermal gravimetric analyzer and X-ray photoelectron spectroscopy.The anti-corrosion performance of the coatings was analyzed by scanning electron microscopy,water contact angle,electrochemical and salt spray experiment.The results show that when the mass fraction of 0.5%PA/PmPD-SiO2 is added,the coating adhesion is grade 0,the pencil hardness is 3H,the impact resistance is 45 kg·cm,the corrosion inhibition efficiency is 97.2%,and the corrosion resistance is the best.The corrosion current density is reduced by 36 times compared with the pure waterborne epoxy(WEP)coating,and the low-frequency impedance modulus is increased by 2 orders of magnitude.
NETL
NSTL
万方数据
