Corrosion inhibition of mild steel in 1 M HCl using water soluble chitosan derivative of vanillin

The water-soluble chitosan derivative (WSCD) was made by mixing chitosan with sodium hydroxide, treating the mixture with chloroacetic acid, and then forming a Schiff base with vanillin in an acidic medium. In this study, we examined the corrosion-inhibiting ability of a WSCD on mild steel surfaces in acidic environments. Weight loss, EIS, PDP, LPS, and OCP measurements were used to study the corrosion resistance on mild steel surfaces in 1 M HCl solutions with known concentrations of WSCD. The results show that WSCD functions effectively as a mixed-type anodic and cathodic inhibitor, providing 87 % corrosion inhibition efficiency at 75 ppm. Using SEM to investigate the morphology of corroded mild steel with and without varying amounts of WSCD, impedance measurements show the development of a thin film of inhibitor on the metal surface, the extent of which increases as the inhibitor concentration rises. The WSCD molecule first adsorbs on mild steel and follows Langmuir adsorption isotherm. It is found that the (∆Gads0)adsorption's free energy is -17.473 kJ/mol. The contact angle measurements confirm that the hydrophobicity of the metal surface has increased as a result of the inhibitor's thin film development.

Investigating the effect of curing temperature on the corrosion resistance of epoxy-based composite coatings for aluminium alloy 7075 in artificial seawater

Araldite LY5052 epoxy resin and Aradur HY5052 hardener were used in a ratio of 100 : 38 to produce composite coatings containing 0.05 proportion of functionalized SiO₂. Coating samples were cured at curing temperatures of 60, 80, 100, 120, and 140 °C. The results of Fourier Transform Infrared Spectroscopy (FTIR) verified that silica particles were successfully functionalized with methyltrimethoxysilane (MTMS)/3-aminopropyl-triethoxysilane (APTES). The epoxide and Si-O bond peaks in the EHS100 coating were present due to the effective incorporation of functionalized silica (FSiO₂) particles in the polymeric matrix (epoxy resin). The surface morphology of the bare aluminium alloy AA7075 and EHS100 coating was investigated by Field Emission Scanning Electron Microscopy (FE-SEM). Additionally, corrosion analysis was conducted at room temperature using an electrolytic solution of artificial seawater, prepared according to ASTM standard D1141-98. Charge transfer resistance (R_ct) was shown to increase by 86.43, 92.15, 94.76, 90.65, and 83.96% for EHS60, EHS80, EHS100, EHS120, and EHS140 in comparison to bare AA7075 substrate using electrochemical impedance spectroscopy (EIS) examination. Furthermore, potentiodynamic polarization (PDP) measurements were carried out to determine the corrosion rates, which demonstrated a drop of 55.98, 98.96, 99.37, 98.33, and 50.39% for EHS60, EHS80, EHS100, EHS120, and EHS140, as compared to the bare AA7075 sample. The highest charge transfer resistance (29.77 kΩ) and lowest corrosion rate (0.00078 mm per year) were recorded for EHS100, which reveals that the EHS100 coating has the best anti-corrosion performance and provides the maximum corrosion protection for the aluminium alloy AA7075 substrate.

Analysis of Combustion Process of Protective Coating Paints

Structural elements in buildings exposed to high temperature may lose their original stability. Application of steel structures has several advantages; however, deflection under exposure to high temperatures may be a potential obstacle. Therefore, the aim of the study was to determine how temperature affects decomposition of protective paints applied in the construction. A dedicated installation for the analysis of the combustion process of protective coating paints in a laboratory scale was prepared. The experimental device consisted of the following parts: top-loading furnace connected to the gas conditioner, the LAT MG-2 gas mixer, and portable gas analyzer GASMET DX-4010. The following type of the protective powder coating paints were analyzed: alkyd and polyurethane. The obtained results indicated that during thermal decomposition of paints, formaldehyde, benzene, heptane, and butanol were released, however in different concentrations. Moreover, decomposition temperature affected the type and amount of released gas mixture components. With increasing temperature, increased release of formaldehyde and benzene was noticed, while the concentration of butanol and heptane decreased. Finally, the product of thermal decomposition emitted in the highest concentration was formaldehyde, which can cause irritation and sensitization in humans.

Fabrication and characterization of a Fe3O4/polyvinylpyrrolidone (Fe3O4/PVP) nanocomposite as a coating for carbon steel in saline media

Corrosion of carbon steel (CS) is a security and financial concern for numerous industries involving oil, petroleum, and automotive industries.

Anticorrosion Properties of Epoxy Composite Coating Reinforced by Molybdate-Intercalated Functionalized Layered Double Hydroxide

Herein, an intercalation modification technique is proposed to improve the anticorrosion performance of polymeric coatings. Molybdate, an inhibitor, was intercalated to bestow inhibitive attributes, while functionalization of the layered double hydroxide (LDH) reservoir was performed to augment the interfacial adhesion of LDH with the polymer matrix and steel surfaces. The intercalation and functionalization of Mg–Al–LDH was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. The corrosion inhibition effectiveness of the prepared composite coating was analyzed using potentiodynamic polarization and electrochemical impedance spectroscopy. The electrochemical results revealed that the protective performance of epoxy coating was significantly enhanced by the addition of functionalized double hydroxide. The corrosion protection efficiency of the composite coating was improved by more than 98%, while the corrosion rate was lowered by ~98%, respectively, with the addition of 1 wt.% of functionalized LDH.

Waterborne reduced graphene oxide dispersed bio-polyesteramide nanocomposites: an approach towards eco-friendly anticorrosive coatings

RGO dispersed waterborne soy polyester amide nanocomposites were formulated utilizing a solventless VOC free green approach for use as low cost anticorrosive coatings.

Exploring corrosion protection properties of alkyd@lanthanide bis-phthalocyanine nanocomposite coatings

Organic coatings have been widely used to protect carbon steel pipelines from external corrosion; however, they often suffer from permeability and weak adhesion. Here we show that synthetic lanthanide bis-phthalocyanine complexes, LnPc₂ (Ln = lanthanide metal, Pc = C₃₂H₁₆N₈ denotes the phthalocyanine ligand) can be used to form new nanocomposite coatings to provide corrosion protection to the underlying carbon steel pipelines. Electrochemical studies (EIS and potentiodynamic polarization) showed that the incorporation of LnPc₂ compound (PrPc₂, SmPc₂ and HoPc₂) additives with alkyd coating, leads to a significant increase in the corrosion resistance of carbon steel in 0.5 M HCl solution. The alkyd@LnPc₂ nanocomposite coatings absorb very low water volumes, when compared to the neat alkyd coating. LnPc₂ compounds allowed enhancing the pull-off adhesion of coatings performance from 3.34 MPa to 19.94 MPa. The efficiency of alkyd@HoPc₂ coating appears higher than that of alkyd@PrPc₂ and alkyd@SmPc₂ coatings. The protective properties of alkyd@LnPc₂ coatings were confirmed by SEM, TGA, scratch hardness, impact resistance, bend test and contact angle analysis.

Organic coatings have been widely used to protect carbon steel pipelines from external corrosion; however, they often suffer from permeability and weak adhesion.

High performance anti-corrosive epoxy–titania hybrid nanocomposite coatings

Mechanical stability, surface hydrophobicity, and thermal stability of anticorrosive polymeric coatings play a significant role in technological and industrial fields.

Sunflower oil-based hyperbranched alkyd/spherical ZnO nanocomposite modeling for mechanical and anticorrosive applications

Approaches for designing advanced nanomaterials with hyperbranched architectures and lack of volatile organic content (VOC) have attracted considerable attention.

Bio-inspired electrochemical corrosion coatings derived from graphene/natural lacquer composites

To develop green efficient anti-corrosion coatings, graphene/lacquer composite coatings were demonstrated.

Protection of carbon steel corrosion in 3.5% NaCl medium by aryldiazonium grafted graphene coatings

Modification of CS/G by 1,8 ND containing two phenyl rings and two azo groups led to higher protection efficiency.

Enhanced corrosion resistance of polybenzoxazine coatings by epoxy incorporation

Polybenzoxazine/epoxy composite coatings with a dual-crosslinking network have been developed for anti-corrosion, and exhibit stable hydrophobicity even after the potentiodynamic measurements.

Soy polyester urethane/TiO2 and Ce-TiO2 nanocomposites: preparation, characterization and evaluation of electrochemical corrosion resistance performance

Eco-friendly soy polyester urethane nanocomposite coating materials were prepared by dispersing TiO₂ and Ce-TiO₂ nanoparticles in a 3-isocyanatopropyltriethoxysilane (IPTES) modified soy oil (SO) polyester urethane (PEUTES) matrix.

Development of sustainable resource based poly(urethane-etheramide)/Fe2O3 nanocomposite as anticorrosive coating materials

Linseed polyetheramide (LPEtA) resin was synthesized by the condensation polymerization of N-N-bis (2-hydroxyethyl) linseed oil fatty amide (HELA) with pyrogallol. The residual hydroxyl groups of LPEtA resin were further modified with isophorone diisocyanate (IPDI) to obtain linseed poly(urethane-etheramide) (ULPEtA) via addition polymerization. ULPEtA was modified with iron oxide nanoparticles in different weight percent (0.1 wt%, 0.2 wt%, 0.3 wt% and 0.4 wt%) producing ULPEtA/Fe2O3 nanocomposite. Spectroscopic characterization of HELA, LPEtA and ULPEtA was carried out by using Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR) and carbon nuclear magnetic resonance (13C-NMR) techniques. Physicochemical and physico-mechanical properties of LPEtA and ULPEtA were carried out by using standard methods. Thermal stability and anticorrosion performance were assessed by thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and potentiodynamic polarization. The corrosion behavior of ULPEtA/Fe2O3 nanocomposite coatings on mild steel was investigated in different corrosive environments (3.5 wt% HCl, 5.0 wt% NaCl, 3.5 wt% NaOH, and tap water) at room temperature. Surface morphology study was performed through scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Coating properties such as gloss, scratch hardness, flexibility and impact resistance were evaluated using standard methods. The results of this study showed that ULPEtA/Fe2O3 nanocomposite coatings exhibit good physico-mechanical, anticorrosive properties and can be safely used up to 220°C.

Linseed oil polyol/ZnO bionanocomposite towards mechanically robust, thermally stable, hydrophobic coatings: a novel synergistic approach utilising a sustainable resource

Linseed polyol/ZnO bionanocomposite produced strong, well-adherent, flexibility-retentive, thermally stable, hydrophobic, “green” corrosion protective coatings via an in situ solventless “green” approach.

Influence of microwave irradiation on various properties of nanopolythiophene and their anticorrosive nanocomposite coatings

The time and energy efficient microwave synthesis of nano polythiophene provides higher yield, smaller particle size, superior physico-mechanical properties and promising corrosion inhibition properties as compared to conventional synthesis.