Development and Investigation of a Polyarylene Ether Nitrile Coating Material as Corrosion Protection for Metal Substrates

In this research, a novel polyarylene ether nitrile (PEN) coating material was fabricated through a facile stepwise polymerization method, which provides metallic substrates used in the oil industry with remarkable corrosion protection performance. A variety of characterization techniques were employed to evaluate the comprehensive properties of the PEN coating materials against a commercially established high-temperature-resistant epoxy coating. Based on the TGA curves, the PEN3 coating exhibited a T5% value of 521 °C, which was 44.72% higher than that of the epoxy coating. According to the tensile experiment, the PEN coatings demonstrated improved mechanical performance, achieving tensile strength and breaking elongation values of 89.37 MPa and 7.14% (PEN3), respectively, while the epoxy achieved values of 18.67 MPa and 0.32%, respectively. EIS tests revealed that all the PEN coatings exhibited superior corrosion resistance compared to the epoxy coating. Among them, the PEN3 coating remained intact without failure and showed the highest impedance value (5.665 × 107 Ω·cm2), which was two orders of magnitude higher than epoxy. Our research confirmed that the PEN coating material provided enhanced corrosion resistance, thermal stability and mechanical properties, positioning it as an alternative option to replace epoxy coating in prolonging the service life of steel piping in oil field applications.