Graphene oxide modified tung oil-based vinyl ester coating with improved anti-corrosion performance

Vinyl ester resin (VER) has been regarded as one of effective anti-corrosive resins, which is commonly used in anti-corrosion coating fields. However, the barrier effect of VER-based films against the corrosion medium is seriously reduced due to the inevitable generation of pores and cracks during the VER-based film formation process. In this work, the modified lamellar graphene oxide (GO560) nanoparticles used as functional fillers are introduced into the VER-based film matrix to address the above issue. Herein, GO nanoparticles are modified by epoxy-terminated silane coupling agent (KH560) to improve their dispersibility and hydrophobicity. And then the GO560 nanoparticles are bridged with VER through the tung oleic acid maleic anhydride (TOAMA). The study results of stand test, Fourier infrared spectrum (FTIR), scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) indicate that the ring opening reaction of carboxylic anhydride (TOAMA) with epoxy groups from GO560 nanoparticles and epoxy resin assists in the good dispersibility of GO560 nanoparticles in the VER composite film matrix. Moreover, the electrochemical impedance measurement shows that the low-frequency impedance of GO560/VER films (7.08 × 1010 Ω cm2) is 4 orders of magnitude higher than that of Blank/VER film (1.11 × 107 Ω cm2) after 100-day immersion in 3.5 wt% NaCl solution, which implies the obviously improvement of corrosion resistance for VER-based film by introducing GO560 nanoparticles. This study provides a promising method for uniformly dispersing the epoxidized GO nanosheets by the bridged linkage effect of bio-based materials into VER-based film, and then construct multifunctional nanosheets-VER composite tough films with the favorable and long-lasting anti-corrosion performance, which have the great potential in the marine anti-corrosion application including ships and marine engineerings.