Corrosion resistance of graphene/waterborne epoxy composite coatings in CO2-satarated NaCl solution.

Hao Xu,Hongmei Wang,Yongjun Li,Yun Li,Haijun Hu

doi:10.1098/rsos.191943

Abstract

This study investigated the corrosion resistance of graphene/waterborne epoxy composite coatings in CO2-satarated NaCl solution. The coatings were prepared by dispersing graphene in waterborne epoxy with the addition of carboxymethylcellulose sodium. The structure and composition of the coatings were characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared and Raman spectroscopies. The corrosion resistance of the composite coatings was investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Composite coatings with more uniform surfaces and far fewer defects than blank waterborne epoxy coatings were obtained on 1020 steel. The 0.5 wt% graphene/waterborne epoxy composite coating exhibited a much lower corrosion rate and provided better water resistance properties and long-term protection than those of the blank epoxy coating in CO2-satarated NaCl solution.

Highlights

The CO2 corrosion of pipelines is attracting more and more attention in the oil and gas industry because of the CO2enhanced oil recovery [1]
We investigated the corrosion resistance of graphene/waterborne epoxy composite coatings in CO2satarated NaCl solution and discussed the corrosion mechanism of the composite coatings
Raman spectra were recorded to identify if interactions between the Carboxymethylcellulose sodium (CMC) and graphene sheets occurred during coating preparation

Summary

Introduction

The CO2 corrosion of pipelines is attracting more and more attention in the oil and gas industry because of the CO2enhanced oil recovery [1]. In this process, by injecting CO2 into oil and gas fields, the residual oil and gas can be pushed out to improve oil recovery. CO2 corrosion is the main form of internal corrosion failure in oil and natural gas pipelines [2]. During the CO2 flooding test in the Little Creek Oilfield, USA, the wall of the oil extraction pipe was corroded and perforated within five months with a corrosion rate of 12.7 mm yr−1 [3]. Pipeline corrosion resulted in billions of dollars in losses to the oil and royalsocietypublishing.org/journal/rsos R.

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