Abstract
Corrosion of oil and gas pipelines significantly reduces the service life of the pipelines, thus increasing costs, and more seriously, it can cause catastrophic environmental accidents. More recently, the exploitation of oil in ultra-deep seawater fields is facing new technological challenges in material selection owing to the extreme production conditions. Thus, the development of organic coatings as protective layers for steel pipelines is of crucial importance against highly corrosive environments. In this work, fusion bonded epoxy (FBE) coatings were deposited onto chemically functionalized carbon steel surfaces with organosilanes to investigate the potential applications in protection against corrosion and degradation in harsh marine environments. Carbon-steel API 5L X42 (American Petroleum Institute Standard grade) was chemically functionalized with two organosilanes, 3-APTES [(3-Aminopropyl)triethoxysilane], and 3-GPTMS [(3-Glycidyloxypropyl)trimethoxysilane], followed by the deposition of FBE composite coatings. The systems were extensively characterized with respect to each component as well as the steel-coating interface. The contact angle measurements and Fourier transform infrared spectroscopy (FTIR) results clearly indicated that the steel surface was effectively modified by the functional amine and glycidyl silane groups, leading to the formation of interfacial covalent bonds with increased hydrophobicity compared to bare steel surfaces. In addition, the morphological and chemical characterizations of FBE by scanning electron microscopy, atomic force microscopy, X-ray diffraction, and FTIR showed that it is composed of an epoxy-based organic matrix of bisphenol-A diglycidyl ether (DGEBA) reinforced with uniformly dispersed inorganic phases of calcium silicates and TiO2 particles. Moreover, the chemical functionalization of the steel surfaces with amino and glycidyl silanes significantly altered the interfacial forces with the FBE coatings, resulting in higher adhesion strength for 3-APTES-modified steel compared to 3-GPTMS-steel; however, both mostly showed cohesive rupture mode in the FBE component.
Highlights
The global oil and gas industry has been developing rapidly owing to the discovery of oil fields at ultra-deep seawater, and this has posed several new challenges for the exploitation and production of petroleum
Fusion-bonded epoxy (FBE) coatings or a combination of fusion-bonded epoxy (FBE) with other materials forming multilayers are widely used for corrosion protection of gas/oil pipelines [8,9,10]
There have been a few studies on the use of steel that is chemically modified by silanes for improving the adhesion with epoxy coatings [13, 14], no report was found in the consulted literature in which a system composed of steel-primer-FBE was systematically and extensively characterized by considering each individual component and the interfaces between them
Summary
The global oil and gas industry has been developing rapidly owing to the discovery of oil fields at ultra-deep seawater, and this has posed several new challenges for the exploitation and production of petroleum Materials used in these conditions are subjected to extreme pressure, temperature, and corrosion and the associated technological issues must be addressed with consideration of engineering, economic, and environmental constraints [1,2,3]. Epoxy-based polymers such as FBE are the widely used for gas/oil pipelines because they exhibit high chemical resistance, very low permeability to chloride ions, good mechanical flexibility, strong adhesion to steel, and suitable processing characteristics, leading to improved corrosion protection and operational lifetime of the pipelines. The main goal of this study was to prepare hybrid organic–inorganic FBE coatings using sol–gel chemistry for the functionalization of the steel surfaces to improve the interfacial properties for improved adhesion and protection against corrosion
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
