Waterborne methylamine adduct as corrosion inhibitor for surface coatings

Soybean oil was epoxidized using peracetic acid prepared in situ from aceti c acid and hydrogen peroxide with Dowex 50 W-8X as a catalyst. The epoxidiz ed soybean oil was allowed to react with methylamine. The resulting adduct was identified and emulsified. The emulsified methylamine adduct was added at different: concentrations to an emulsion (styrene/acrylic)-based paint ( blank). The effect of the methylamine adduct concentration on the physical, chemical, and mechanical properties of the paint was studied. Various test s such as metal substrate weight; loss, corrosion, blister, and scratch res istance were performed to evaluate the efficiency of the prepared adduct. f t was found that there is an optimum concentration at which the methylamine adduct is very effective as a corrosion inhibitor. This concentration is a bout 0.5% by weight. In comparison with chromate anticorrosive pigment, it was found that the methylamine adduct is superior with more economical and environmental advantages. (C) 2001 John Wiley & Sons, Inc.