Preparation Of Metal Inhibitor And Enhancement For Waterborne Epoxy Coating

This paper studied two corrosion inhibitors aniline trimers (AT) and epoxy Phosphate (HEP) for carbon steel corrosion resistance and their application in aqueous epoxy resin, Specific research contents and results are as follows:1 Aniline trimer (AT) was prepared by chemical oxidation which is an inhibitor containing three N AToms. FTIR, UV-visible spectroscopy and nuclear magnetic resonance spectroscopy (NMR) was used to characteriz-e its structure. Polarization curve, AC impedance spectroscopy (EIS) and static corrosion weight loss test were used to evaluate the corrosion inhib-ition of AT in lmol/L HC1 solution, scanning electron microscope (SEM) analysis of its surface. Studies had shown that AT inhibitor on metal had good corrosion performance, when the AT content was 100 mg/L its inhib-ition efficiency was up to 99%. Langmuir adsorption isotherm model and EDS were used to study the mechanism of metal corrosion; the results showed that AT could form a film on carbon steel surface, thus effectively blocked the steel surface in contact with the hydrochloric acid solution, so that metal could be protected,2、Epoxy phosphate(HEP) was prepared with E44 and phosphoric acid (the ratio of epoxy group and hydroxyl group molar is 3.0:2.5) and FT-IR was used to characterize its structure and proved the reaction between E44 and phosphoric acid. Then we added HEP as a corrosion inhibitor to waterborne epoxy resin to make the paint with rust. The corrosion inhib-ition performance was investigated by polarization curves and electro-chemical impendence spectroscopy (EIS). The results showed that it can improve the corrosion resistance with HEP. The tafel curves showed that the Rp of the electrode with HEP is much higher than the blank one indi-cating that the electrode with HEP had a lower corrosion rate than the blank one, which was consistent with the EIS results.3、We prepared waterborne epoxy coatings using AT as a corrosion inhi-bitor by adding AT 0,0.1%,0.3% and 0.5%, then the physical perform-ance and corrosion resistance were tested. The results showed that:the alkali resistance and salt resistance of waterborne epoxy coating are better than acid resistance; there is little influence on the physical performance with adding AT, whereas it improved the corrosion resistance of the coating and the coating had the best corrosion resistance with 0.1% AT.4、DSC was used to study the reactivity between AT and epoxy groups by replacing waterborne epoxy resin with phenyl glycidyl ether, the results showed that AT can react with epoxy groups. Therefore, prepared a series of aniline trimer-waterborne epoxy coatings used AT as part of curing agent. Then the physical performance of aniline trimer-waterborne epoxy coatings were tested as good as the waterborne epoxy coatings. It can be seen from the EIS that aniline trimer-waterborne epoxy coatings have better corrosion resistance.