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

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 = 10(7) ohm cm(2) and phase angle = 85.6 degrees) in comparison to those of WBPEA-PMF-80 (impedance = 10(6) ohm cm(2) and phase angle = 82 degrees) and other such reported coatings.