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Garcinia gummigutta vegetable oil (GGVO) is a rich source of stearic and oleic acid which on heat treatment at around 300 °C, will get polymerized with highly conjugated network system. The present work intended to exploit the properties of GGVO for the production of eco-friendly anti-corrosion coating material. The oil extracted from GG seeds was...
Citations
... Several authors have reported the use of vegetable oils as renewable raw materials for the synthesis of polymers [9][10][11][12][13]. Vegetable oils can be the competing alternative to the petro-based polymer products due to their diverse abundance and the functional group flexibilities in their backbone structure such as double bonds, epoxies and hydroxyls which pave way for variety of modifications through chemical reactions [13,14]. ...
... graphene oxide, carbon nanotubes, carbon nanofibers, etc., as nanofillers to improve anti-corrosion performance of polymer coatings. The carbon-based nanomaterials have been proved to show good barrier properties due to their large specific surface area [6,7,14,16,17]. ...
Graphene nanoribbon (GNR) is a flat ribbon-like 1D nanomaterial of graphene family rarely explored in the development of anti-corrosion coatings. In the present work, a bio-based anti-corrosion coating was fabricated using GNR as nanofiller in malenized linseed oil (MLO) polymer network. MLO polymer network was first prepared from commercially available linseed oil by malenization reaction at 80 °C using maleic anhydride. Later, GNR was synthesized from multiwalled carbon nanotube by oxidative unzipping method and incorporated into MLO polymer network to obtain the bio-based MLO–GNR nanocomposite. The as-prepared MLO and MLO–GNR coating materials were spin coated onto bare mild steel samples and cured at 80 °C for 24 h. The morphology and surface characteristics of coatings were studied by spectroscopic and microscopic techniques. Further, the anti-corrosion behaviour of bare and coated MS samples was investigated by potentiodynamic polarization and electrochemical impedance methods in a 3.5% NaCl medium. Among the samples, MLO–GNR-coated samples exhibited a high level of corrosion inhibition in the saline medium compared to uncoated MS sample as the damages and destruction activity were more on its surface than their counterparts. MLO–GNR nanocomposite coating exhibited robust corrosion resistance activity and showed 99.9% protection efficiency. Further, the MLO–GNR coating displayed higher stability in the saline medium as well as open-air environment establishing that the flat GNR molecule acts as excellent nanofiller in MLO polymer network to produce robust anti-corrosion activity leading to protection of mild steel.
Graphical abstract
The present work demonstrates the as-prepared silver (Ag)-decorated reduced graphene oxide (rGO) nanohybrid–sulfonated polyaniline (SPANI) as a highly efficient anti-corrosion coating material for mild steel (MS) corrosion. In this direction, graphene oxide (GO), rGO-Ag and rGO-Ag-SPANI were synthesized and characterized by Fourier transform infrared (FT-IR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectral studies. Different weight ratios of rGO-Ag and SPANI were dispersed in epoxy (EP) resin and coated on the MS surface by spin coating technique. The coated nanocomposites were examined by SEM, atomic force microscopy (AFM) and contact angle analyses. Electrochemical corrosion measurements of different compositions rGO-Ag and SPANI were carried out to analyze the influence of rGO-Ag-SPANI nanofiller in enhancing the anti-corrosion and barrier properties of EP resin. Results indicate that 1:2 composition of rGO-Ag and SPANI-dispersed epoxy coating (GASP-3) showed good corrosion protection against the corrosive electrolyte, and the value of |Z|0.01 Hz was found to be in the order of 106 Ω cm2. Further, the highest contact angle value of 93.4° in GASP-3 coating substantiates the electrochemical results. This could be ascribed due to the presence of more SPANI molecules in the coating matrix which effectively block the passage of corrosive electrolytes through the micropores of epoxy resin.
This article describes the synthesis of polyesteramide (PEA) resin from Leucaena leucocephala oil (LLO) obtained from seeds of L. leucocephala tree, locally grown in King Saud University Campus. LLO was transformed into amide diol by based catalyzed amidation reaction, followed by esterification reaction with malic acid (MA), that resulted in LLO-based PEA (LPEA). The synthesis was performed without using any solvent or catalyst. Fourier-transformation infrared spectroscopy and nuclear magnetic resonance confirmed the formation of LPEA by the introduction of amide and ester moieties. LPEA was further reinforced with nano graphene oxide (GO) and fabricated into nanocomposite corrosion protective coatings (LPEA/GO). LPEA/GO coatings obtained were tough, flexibility retentive and showed good corrosion resistance performance toward 3.5 w/w% NaCl medium. Thermogravimetric analysis confirmed good thermal stability of coatings with safe usage up to 200°C.
Metals corrode easily which leads to environmental hazards, structural cracks and economic loss. To mitigate metals from corrosion, the organic coating was preferred since it aids as a barrier to separate oxygen, corrosive ions and water. However, some organic inhibitors are toxic in some extent. The significance of the research is to deepen the corrosion studies using natural biopolymer materials especially rich in nitrogenous matter. Zinc oxide, titanium dioxide, papaya leaves and DGEBA (diglycidyl ether of bisphenol A) were used in this study. The presence of alkaloid material and nitrogenous matter in the papaya leaf provides a beneficiary effect by accelerating the corrosion resistance in carbon steel. Mechanical properties/electrochemical behavior of carbon steel was studied by impedance and polarization test in an acidic environment. The microhardness of nano-hybrid composite was found to be 800 HV200 with surface wettability of 109.5° (hydrophobic). In addition, corrosion rate of composite coating was reduced by 79% and 22.5% from virgin and DGEBA coating medium, respectively. An acoustic emission (AE) test was also taken to monitor the characterization of these materials. The acoustic emission parameters are within the error margin of around 60% of the operating load. Microstructural analysis shows the morphological behavior of the coated substrate. Biopolymer shows a prominent anti-corrosive performance for carbon steel at 0.5 mol/L. The results are justified in comparison with nano-hybrid composite biopolymer coating (ZnO–TiO2–PLE) to the organic polymer coating (DGEBA).
The synthesis of graphene based composite materials by simple environment friendly method is of prime importance. So, we report the synthesis of reduced graphene oxide-iron oxide (rGO-Fe2O3) nanocomposite by the solution combustion method. The rGO-Fe2O3 is employed as a nanofiller material in epoxidized linseed oil (ELO) based anti-corrosion coating. To ensure environmental sustainability, the curing agent for ELO resin is also prepared by using linseed oil. The synthesized rGO-Fe2O3, resins, and curing agent were well characterized by X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) and Proton nuclear magnetic resonance (¹H NMR) techniques. The mild steel coupons coated with the nanocomposite were analyzed for their stability and anti-corrosion behavior using scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle, and electrochemical studies. Electrochemical impedance data showed that the ELO-rGO-Fe2O3 coating showed a very large Rc value (8.874×10⁷ Ω cm²) and significantly low capacitance (3.63×10-10 F cm²) when compared to ELO coating, indicating its excellent corrosion resistivity. Further, corrosion protection ability was observed up to 44 days in 3.5 wt% NaCl solution. The results indicate that the rGO-Fe2O3-ELO composite coating acts as a durable and sustainable substitute for petroleum-based coating and can find potential applications in coating industries.
The present work intended to develop linseed oil-based anti-corrosion nanocomposite coating material. In this context, the epoxy resin was prepared by the epoxidation of linseed oil (ELO). Curing agents (H1 and H2) were also prepared by the malenization of linseed oil, and condensation of malenized linseed oil with diethylenetriamine. A simple eco-friendly method was employed for the reduction of graphene oxide using 10% sodium hydroxide solution. The composite coating material was prepared by direct incorporation of the reduced graphene oxide (rGO) into the linseed oil without using any organic solvent. The stability, surface morphology, and anti-corrosion properties of the coated materials were examined by Thermogravimetric analysis (TGA), Atomic force microscopy (AFM), Scanning electron microscopy (SEM), X-ray diffraction (XRD), water contact angle measurements, and electrochemical studies. Electrochemical data indicated that the corrosion rate of mild steel is reduced to around 5000 times for the rGO-ELO-H2 system with protection efficiency of 99.98% and the exhibited stability up to 10 days in 3.5 wt% NaCl solution.
Epoxy is extensively used for anti-corrosion coatings on metallic materials. Conventional epoxy coatings have a permanent crosslink network that is unable to repair itself when cracks and damages occur on the coating layer. This study aims to develop self-healing epoxy vitrimer/carbon nanotube (CNTs) nanocomposite for coating. Two bio-based curing agents viz., cashew nut shell liquid (CNSL) and citric acid (CA) were employed to create covalent adaptable networks. The 0–0.5 wt% CNTs were also incorporated into epoxy/CNSL/CA matrix (V-CNT0-0.5). Based on the results of our study, thermomechanical properties of V-CNT nanocomposites increased with increasing CNTs content. The bond exchange reaction of esterification was thermally activated by near infrared (NIR) light. The V-CNT0.5 showed the highest self-healing efficiency in Shore D hardness of 97.34%. The corrosion resistance of coated steel with V-CNT0 and V-CNT0.5 were observed after immersing the samples in 3.5 wt% NaCl for 7 days. The corrosion rate of coated steel with V-CNT0.5 decreased from 9.53 × 10² MPY to 3.12 × 10–5 MPY whereas an increase in protection efficiency of 99.99% was observed. By taking advantages of the superior self-healing and anti-corrosion properties, V-CNT0.5 could prove to be a desirable organic anti-corrosion coating material.
The present work destined to enhance the anti-corrosion performance of the epoxy resin (EP) by incorporating the functionalized multi-walled carbon nanotube/polyindole (f-MWCNT/PIn) nanocomposite in the EP matrix. In this direction, the f-MWCNT and f-MWCNT/PIn were prepared, and their chemical compositions were confirmed by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) studies. The corrosion resistance property of different weight percentages of f-MWCNT/PIn dispersed EP coatings on mild steel (MS) in 3.5 wt% NaCl solution was examined by the electrochemical technique. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization results indicated that 0.25 wt% f-MWCNT/PIn blended nanocomposite coating exhibits excellent anti-corrosion and barrier protection properties. Uniform dispersion of nanofiller and increasing the pathway of the corrosive electrolytes make it an excellent coating material in anti-corrosion applications.
