Vanillin and organosilicon functionalized graphene oxide modified ester resin composite coatings with excellent anti-corrosion properties

Abstract

Epoxy vinyl ester resin is widely used in the field of corrosion protection because of its excellent corrosion resistance and mechanical properties. However, due to the ease of hydrolysis of the ester group in the ester resin, the barrier ability of the coating is reduced, which will accelerate metal corrosion. The existing literature shows that the use of nano-sheet materials such as graphene oxide (GO) can effectively enhance the barrier properties of the coating. In order to solve the poor compatibility and electrical corrosion phenomenon of GO, in this work, renewable vanillin and silicone with excellent anti-corrosive properties were grafted to GO (APGO) by insertion reaction and D-A reaction. Subsequently, a series of new APGO-based epoxy vinyl ester resin composites with excellent mechanical properties and anti-corrosion properties were prepared by thermal crosslinking polymerization. The results showed that when the additive amount of APGO was 0.1 wt%, the comprehensive performance of the composite was the best: the conductivity (1.9 × 10−13–5.6 × 10−13 S/cm) of the composite was far lower than the critical electrical insulation value (10−9 S/cm), the breaking strength was improved by 38.0 %, the contact angle was increased by 65.7 %, and its anti-corrosion efficiency was up to 99.03 %. After 70 days of immersion in 3.5 wt% salt water, the impedance modulus of the composite at low frequency (Zf = 0.01 Hz) remained 2.23 × 1010 Ω cm2, which was 2 orders of magnitude higher than that of pure epoxy vinyl ester resin (2.43 × 108 Ω cm2). The above results were not only related to the maze effect formed by APGO, but also related to the increased crosslinking density of the system. This work provided a novel strategy for preparing GO-based composites with excellent comprehensive properties.