Synthesis of graphene oxide functionalized by phytic acid for anticorrosive reinforcement of waterborne epoxy coating

Graphene derivatives are excellent fillers for providing outstanding barrier performance in organic protective coating but no active inhibition property. In this paper, a facile and environmentally friendly strategy is presented to improve the anticorrosion ability of graphene by modifying graphene oxide (GO) with a green corrosion inhibitor derived from nature, phytic acid (PA). The as-prepared PA modified GO (PAGO) thus possesses the passive barrier property and active corrosion inhibition function simultaneously. Employing PAGO as filler, a high-performance waterborne epoxy composite coating (PAGO/WEP) with “barrier + inhibitor” double anticorrosion effect was fabricated. The EIS test results demonstrated that after 21 days of immersion, the impedance modulus of the PAGO/WEP coating did not decrease and still maintained at the initial impedance value. The salt spray tests also demonstrated the significantly enhanced anticorrosion performance.