Research Article Effect of High Temperature Sodium Hydroxide Immersion on Fusion Bond Epoxy Coating Amal Al-Borno, Xianyi Chen, and Shailesh Kewaldas Dhoke Charter Coating Service (2000) Ltd., No. 6, 4604-13 Street NE, Calgary, AB, Canada T2E 6P1 Correspondence should be addressed to Shailesh Kewaldas Dhoke; shailesh zeo@redifmail.com Received 30 June 2015; Accepted 7 September 2015 Academic Editor: Yu Zuo Copyright © 2015 Amal Al-Borno et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Fusion Bond Epoxy (FBE) coating system was exposed to 5% sodium hydroxide at elevated temperature for 30 days. Te result of exposure showed formation of adhere deposit layer, a discolored zone underneath and remaining un-afected bulk of the coating. Te deterioration of the coating was characterized using analytical techniques like scanning electron microscopy (SEM), energy-dispersive X-ray (EDAX) spectroscopy, attenuated total refection-Fourier transform infrared spectroscopy (ATR-FTIR), diferential scanning calorimetry (DSC), pull-of adhesion, and electrochemical impedance spectroscopy (EIS). Results obtained indicated chemical deterioration of the coating in the discolored zone and leaching of low molecular weight coating component forming deposit layer. Although the adhesion strength and barrier property were not afected, the polymer matrix in the afected zone undergoes severe changes in its surface microstructure, primary chemical structure, and glass transition temperature. Tis may infict serious impairment of the coating functional properties and premature failure of the coating in long term exposure. 1. Introduction Polymeric coating employed on a steel surface is one of the most efective way to combat corrosion. FBE coating in par- ticular is well appreciated as an anticorrosive coating system in coating industry [1]. With the continuous changes in new exposure conditions involving high operating temperatures, the demand for FBE coating that can resist the hostile envi- ronments like corrosive chemicals and reagents is growing. It is well known that coatings are susceptible to chemical degradation especially in immersion condition at the elevated temperature. Chemical degradation of the coating in service may afect both the barrier property and mechanical strength of the coating material. Te degradation of polymer materials can be classifed as physical degradation (e.g., swelling), chemical degradation (e.g., hydrolysis and oxidation), or both [2]. Depending upon the type of degradation a possible failure mechanism can be evaluated. Terefore, knowledge of degradation mechanism of these coating systems in harsh chemical environment is the immediate need of time, in order to predict their life expectancy and to improve the design techniques of industrial equipment and their components. Many studies have been carried out on the degradation of FBE coating immersed in diferent media. For instance, electrochemical impedance spectroscopy study of the FBE coating immersed in 1.5 mol/L NaCl showed severe degra- dation of the coating [3]. In another study, EIS was used to monitor the degradations of a series of carbon black loading in FBE coatings which were exposed to a 3% NaCl solution at room temperature. Te result indicated that the protective performance of the FBE coating was signifcantly improved when the carbon black loading exceeded the threshold con- centration [4]. Study on FBE coated rebars exposed to 3.5% NaCl, chloride-contaminated simulated concrete pore solu- tion, and solid-cast concrete mortars showed that the coating was more prone to the absorption of moisture and chloride in contact with alkaline solution but was very resistant to their difusion in neutral solution [5]. Similarly, FBE coated rebars when exposed to simulated marine environment did not provide total protection to the steel reinforcement in cracked concrete [6]. A case study on the feld performance of FBE mainline and feld joint coatings applied on X100 steel for the transportation of high pressure gas under wet ground condi- tions revealed that the water soak and cathodic disbondment Hindawi Publishing Corporation International Journal of Corrosion Volume 2015, Article ID 903478, 7 pages http://dx.doi.org/10.1155/2015/903478