Waterborne reduced graphene oxide dispersed bio-polyesteramide nanocomposites: an approach towards eco-friendly anticorrosive coatings

Abstract

A waterborne polyesteramide (WBPEA) and its nanocomposites (WBPEA–RGO) were synthesized using soya oil, diethanol amine, phthalic anhydride and RGO nanoparticles. Ethanolic solutions of RGO nanoparticles were dispersed in WBPEA via sonication (WBPEA–RGO) and simultaneously both (WBPEA) and (WBPEA–RGO-x) were cured with 80 phr poly(melamine-co-formaldehyde) isobutylated solution (PMF). Their coatings (WBPEA–PMF-80 and WBPEA–PMF-80–RGO-x) were formulated on finally polished carbon steel strips. The structural elucidation of these materials was performed by FT-IR and NMR spectroscopic analysis. The physico-chemical, physico-mechanical, thermal and anticorrosive properties of these coatings were investigated, which revealed that the nanocomposite coatings possess remarkably good physico-mechanical [impact resistance (150 lb per in.), scratch resistance (11.5 kg), bend tests (flexibility retained up to 1/8 inch)] properties. The nanocomposite coatings show far superior anticorrosive performance (impedance = 10⁷ ohm cm² and phase angle = 85.6°) in comparison to those of WBPEA–PMF-80 (impedance = 10⁶ ohm cm² and phase angle = 82°) and other such reported coatings.