The effect of varying carboxylic-group content in reduced graphene oxides on the anticorrosive properties of PMMA/reduced graphene oxide composites

We present comparative studies on the effect of varying the carboxylic-group content of thermally reduced graphene oxides (TRGs) on the anticorrosive properties of as-prepared poly(methyl methacrylate) (PMMA)/TRG compos- ite (PTC) coatings. TRGs were formed from graphene oxide (GO) by thermal exfoliation. The as-prepared TRGs were then characterized using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Subse- quently, the PTC materials were prepared via a UV-curing process and then characterized using FTIR spectroscopy and transmission electron microscopy (TEM). PTC coatings containing TRGs with a higher carboxylic-group content exhibited better corrosion protection of a cold-rolled steel electrode that those with a lower carboxylic-group content. This is because the well-dispersed TRG with a higher carboxylic-group content embedded in the PMMA matrix effectively enhances the oxygen barrier properties of the PTC. This conclusion was supported by gas permeability analysis.