Study on Modification of Lignin as Dispersant of Aqueous Graphene Suspension and Corrosion Performance in Waterborne G/Epoxy Coating
Though graphene (G) as an excellent protective material for metal, it can aggravate met al corrosion in other side. The modification of sodium lignin sulfonate was achieved by using itaconic acid and acrylamide,which was proved by UV vis and Raman spectra. The modified sodium lignin sulfonate (LAI) with more carboxylic groups can be used as the dispersan t for aqueous graphene suspension. The commercial graphen e can be dispersed uniformly and stability in water v ia p p interaction with LAI at high concentration (6 mg/mL and the LAI G system can be used as an inhibitor in waterborne epoxy coatings too. Electrochemical impedance spectroscope (EIS) and Tafel polarization curves showed that the corrosion performance of waterborne epoxy system with well dispersed G (0.5 wt was remarkably improved compared with pure epoxy coating. Keywords sodium lignin sulfonate, graphene, waterborne epoxy coating, dispersion, corrosion resistance.