Fusion-bonded epoxy composite coatings on chemically functionalized API steel surfaces for potential deep-water petroleum exploration

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 TiO 2 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.

Poly(Phenylene Methylene): A Multifunctional Material for Thermally Stable, Hydrophobic, Fluorescent, Corrosion-Protective Coatings

“…In the panorama of protective coatings against corrosion of polymers with similar application methods and protection mechanism of PPM, there are epoxy resins, especially FBE formulations, and epoxy-polyaniline systems. These two classes of compounds present thermal stability of about 300 • C for epoxides, and about 200-240 • C for polyaniline [19,20]. Moreover, coatings with these polymers are not fluorescent and are also expected to be less hydrophobic than PPM, due to their chemical structures.…”

Tailored Crosslinking Process and Protective Efficiency of Epoxy Coatings Containing Glycidyl-POSS

“…The characteristic bands in the FT-IR absorbance spectra of precursors (DGEBA, GlyPOSS) and formulations D and D-P are evident from Figure 4 and Figure S1, the latter in Supporting Information. The epoxy modes appear in the spectrum of DGEBA at 3056 (νs(C-H)epoxy ring), 1132 (ν(C-O-C)epoxy ether) and 915 (ν(C-O)epoxy ring) cm −1 [5,16,28]. The first two bands are of low intensity and in the proximity of other modes.…”

“…The deposited coatings isolate the metal surface from the atmosphere or any other corrosive media. As a corrosion barrier, the epoxy coatings [4] have been a subject of research and commercial applications for a long time [5]. The well-established routes of their preparation use curing of epoxy-precursors with amino groups-containing compounds; for example, a reaction of diglycidyl ether of bisphenol-A (DGEBA) with dicyandiamide (DICY) curing agent ( Figure 1).…”

“…However, although epoxy coatings are used worldwide as corrosion protective coatings [7], we haven't found any research report on the corrosion topic where the glycidyl-POSS molecules are added to improve the protective efficiency of epoxy coatings. Much more obvious are reports on the addition of different silanes [8] or the application of silane primers [5]. Since the addition of monoglycidyl-heptaisobutyl-POSS nanoparticles can cause phase separation, as hydrophobic isobutyl groups are not compatible with the epoxy network [15], the much easier is to incorporate homoleptic octaglycidyl-POSS (abbreviated GlyPOSS in Figure 1) molecules in the epoxy matrix [24].…”

An assessment of composite repair system in offshore platform for corroded circumferential welds in super duplex steel pipe

“…teel pipelines are commonly used for transportation of fluids over long distance due to its good mechanical properties. However, it becomes corroded as it is exposed to harsh environment without any protection, which causes frequent repair of system or replacement and it ultimately imposes more cost [1][2][3][4]. Traditionally pipelines with severe corrosion problems have to either be repaired using welding technique or replaced by new ones.…”