Degradation mechanisms of amine-cured epoxy novolac and bisphenol F resins under conditions of high pressures and high temperatures

Rajagopalan, Narayanan; Weinell, Claus Erik; Dam‐Johansen, Kim; Kiil, Søren

doi:10.1016/j.porgcoat.2021.106268

Cited by 9 publications

(19 citation statements)

References 47 publications

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Section: Transparent Coating Sample Preparation and Testingsupporting

confidence: 54%

“…In the seawater region, the coating had formed large blisters and flakes, while in the gas phase region, the degradation was less severe. In the hydrocarbon region at the interface with the seawater (HS interface), a discrete redcolored deposition indicates the presence of iron oxide, which was verified by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy in a previous study [3]. Since iron oxide can only be introduced from the substrate, the coating degradation occurred to an extent where the corrosive elements penetrated through the coating network and reached the metal substrate.…”

Section: Transparent Coating Sample Preparation and Testingsupporting

confidence: 52%

“…Furthermore, the sloping cracks are very broad compared to the narrow surface cracks, which could be an indication of initial cathodic delamination of the coating [2]. Such subsurface features were not identified in the previous study of Rajagopalan et al [3] because the analysis was based on surface techniques, including visible light microscopy and SEM. Therefore, spectroscopic techniques were employed to study the chemical signatures of coating degradation present on the surface.…”

Section: Nir Uhr-oct Inspection Of Cracks and Defects In Transparent Coating Samplesmentioning

confidence: 81%

“…The cured sample Figure 1d was subsequently exposed to high pressure and high temperature (HPHT) environment, one of the extreme downhole application conditions of the oil and gas industry. The HPHT conditions in the present study were simulated in an autoclave batch reactor (model 4621, Parr Instruments) equipped with a non-stirred Hastelloy (C276) chamber that is resistant to extreme chemical environments and capable of maintaining temperatures of 350 • C and a pressure of 180 bar [3]. The autoclave and test chamber is shown in Figure 1a,b.…”

Section: Transparent Coating Sample Preparation and Testingmentioning

confidence: 99%

“…Coatings science is in constant development to meet the increasingly demanding requirements of the industry. Protective coatings are particularly important in hostile conditions, such as marine and downhole environments, where underfilm corrosion and coating defects can lead to equipment damage and potentially hazardous situations [1][2][3]. Consequently, it is essential to implement quality control steps for the inspection and testing of coatings at all stages during development and deployment.…”

Section: Introductionmentioning

confidence: 99%

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Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

et al. 2021

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Near- and mid-infrared optical coherence tomography (OCT) is evaluated as a non-destructive and non-contact reflection imaging modality for inspection of industrial and marine coatings. Near-infrared OCT was used to obtain high-resolution images (~6/2 µm lateral/axial) of hidden subsurface cracks and defects in a resin base coating, which had been exposed to high pressure and high temperature to study coating degradation in hostile environments. Mid-infrared OCT was employed for high-resolution (~15/8.5 µm lateral/axial) subsurface inspection of highly scattering marine coatings, demonstrating monitoring of wet film thickness and particle dispersion during curing of a 210 µm layer of antifouling coating, and detection of substrate corrosion through 369 µm of high-gloss alkyd enamel. Combining high-resolution and fast, non-invasive scanning, OCT is therefore considered a promising tool for studying coating performance and for industrial inspection.

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Section: Transparent Coating Sample Preparation and Testingsupporting

confidence: 54%

Section: Transparent Coating Sample Preparation and Testingsupporting

confidence: 52%

Section: Nir Uhr-oct Inspection Of Cracks and Defects In Transparent Coating Samplesmentioning

confidence: 81%

Section: Transparent Coating Sample Preparation and Testingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

et al. 2021

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Surface modification of nano‐SiO₂ and its interaction mechanism in the interface of fiber metal laminates: Experimental and MD simulation analysis

Guo,

Zhan,

et al. 2024

Polymer Composites

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In order to optimize the reinforcing effect of nano‐SiO2 on the interface of fiber metal laminates (FMLs), the nano‐SiO2 was treated by ultraviolet irradiation and silane coupling agent for different surface properties. The interaction mechanisms of nano‐SiO2 were studied by mechanical test, chemical analysis, morphology observation, and molecular dynamics (MD) simulation. The results showed that the average failure strength of FMLs with untreated, hydrophilic and lipophilic nano‐SiO2 increases by 31.80%, 48.77%, and 51.38% compared to the FMLs without SiO2, respectively, and the interface fracture energy for those increases by 31.50%, 74.82%, and 21.47%, respectively. The disparity among the properties is primarily attributed to the surface polarity. The surface group of untreated and hydrophilic SiO2 is hydroxyl, which shows stronger attraction to resin but also easy to agglomerate, while the lipophilic is silane group that shows lower polarity, resulting in weaker attraction to resin but easier dispersion within the resin. Specifically, the surface polarity was verified by characterizing the particle center distance and the number of atoms surrounded by the particle in the two‐particle model. Moreover, the simulation revealed that nano‐SiO2 and resin molecules are mainly connected by chemical bond and hydrogen bond to transfer the load.Highlights The mechanism was explored by experiment and molecular dynamic simulation. The addition of lipophilic SiO2 increased the failure strength by 51.38%. The incorporation of hydrophilic SiO2 enhanced fracture energy by 74.82%. The polarity of the surface group of SiO2 affected the agglomeration/dispersion. The SiO2 and resin were mainly connected by chemical bond and hydrogen bond.

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Epoxidized technical Kraft lignin as a particulate resin component for high-performance anticorrosive coatings

Truncali,

Laxminarayan,

Rajagopalan

et al. 2024

J Coat Technol Res

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Deterioration of steel infrastructures is often caused by corrosive substances. In harsh conditions, the protection against corrosion is provided by high-performance coatings. The major challenge in this field is to find replacements for the fossil-based resins constituting anticorrosive coatings, due to increasing needs to synthesize new environmentally friendly materials. In this study, softwood Kraft lignin was epoxidized with the aim of obtaining a renewable resin for anticorrosive coatings. The reaction resulted in the formation of heterogeneous, solid, coarse agglomerates. Therefore, the synthetized lignin particles were mechanically ground and sieved to break up the agglomerates and obtain a fine powder. To reduce the use of fossil fuel-based epoxy novolac resins in commercial anticorrosive coatings, a series of formulations were prepared and cured on steel panels varying the content of epoxidized lignin resin. Epoxidized lignin-based coatings used in conjunction with conventional epoxy novolac resin demonstrated improved performance in terms of corrosion protection and adhesion properties, as measured by salt spray exposure and pull-off adhesion test, respectively. In addition, the importance of size fractionation for the homogeneity of the final coating formulations was highlighted. The findings from this study suggest a promising route to develop high-performing lignin-based anticorrosive coatings.

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Degradation mechanisms of amine-cured epoxy novolac and bisphenol F resins under conditions of high pressures and high temperatures

Cited by 9 publications

References 47 publications

Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

Surface modification of nano‐SiO₂ and its interaction mechanism in the interface of fiber metal laminates: Experimental and MD simulation analysis

Epoxidized technical Kraft lignin as a particulate resin component for high-performance anticorrosive coatings

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Degradation mechanisms of amine-cured epoxy novolac and bisphenol F resins under conditions of high pressures and high temperatures

Cited by 9 publications

References 47 publications

Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

Surface modification of nano‐SiO2 and its interaction mechanism in the interface of fiber metal laminates: Experimental and MD simulation analysis

Epoxidized technical Kraft lignin as a particulate resin component for high-performance anticorrosive coatings

Contact Info

Product

Resources

About

Surface modification of nano‐SiO₂ and its interaction mechanism in the interface of fiber metal laminates: Experimental and MD simulation analysis