High-performance Anticorrosive Coatings Research Articles

Nanocomposites of Thermosetting Polymers and Graphene Quantum Dots—Physical Attributes and Ongoing Progressions

Thermosets, before hardening, consist of independent macromolecules similar to thermoplastics, however, chemical curing of these macromolecules via heat or radiations may form irreversibly crosslinked macromolecular networks between their main chains. Graphene quantum dots are inimitable spherical nano-entities having the advantages of extremely small sizes, of 5-10 nm, very high surface area, surface/edge effects, quantum confinements and a range of physical characteristics including semiconductivity, fluorescence and magnetic properties. Similar to other nanocarbons (like graphene, fullerene or nanodiamonds), graphene quantum dots have been examined as noteworthy nanofillers to enhance the essential physical features of various macromolecular matrices, such as thermosets, thermoplastics and rubbers. Consequently, this review article was intended to systematically discuss the existing scientific state of graphene quantum dots reinforced thermosetting macromolecular matrices for the formation of high performance nanomaterials. According to the literature reports, the type, amount and molecular weight of these macromolecules seemed to affect the epoxy-quantum dots interactions and physical properties, like strength and heat stability of the resulting nanomaterials. Moreover, including graphene quantum dots in thermosetting matrices, like epoxies, hyperbranched polyesters and hyperbranched polyurethanes, has positively influenced the engineering aspects (mainly mechanical and thermal attributes) of the resulting nanocomposites owing to their interactions, compatibility and interfacial tendencies toward these matrices. Principally, epoxy/graphene quantum dots nanocomposites have been fabricated and investigated for the effects of graphene quantum nano-entities on the physical property enhancements of these irreversibly crosslinked macromolecules due to their mutual matrix-nanofiller interfaces. As per our analysis, the literature hitherto on the graphene quantum dots reinforced thermosetting matrix nanocomposites has disclosed significant property improvements of these macromolecules and their promising technological applications for high performance anticorrosion coatings, electromagnetic interference shields and biomedical fields.

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

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.

Facile self-assembly fabrication of anticorrosive imine-based composite material for excellent protective coatings

Designing suitable additive materials for high-performance anti-corrosion coatings continues to be a formidable obstacle. Although imine molecules are a promising family of organic compounds due to the π-conjugated aromatic structure containing N heteroatoms, their research as the anticorrosive additives is still in its early stages. Herein, we have prepared a rod-like imine molecule, Hexaazatrinaphthalene (HATN), which was further assembled with reduced graphene oxide (rGO) to obtain a novel HATN/rGO composite via a facile electrostatic self-assembly. As such, the HATN/rGO composite as additive material was incorporated into epoxy resin to develop a corrosion-resistant HATN/rGO epoxy coating, showing exceptional passive and active anti-corrosion properties with a low corrosion rate of 5.75 × 10−6 mm a−1 and a high corrosion inhibition efficiency of 99.83 %. Remarkably, the resistance at 0.01 Hz value of HATN/rGO epoxy coating is superior to those of rGO-based epoxy coatings previously reported. Scanning vibrating electrode technique (SVET) and salt spray measurements further demonstrate long-term performance of the HATN/rGO epoxy coating with excellent corrosion resistance. Additionally, theoretical calculation proves that the obvious electron transfer from rGO to HATN molecule promotes charge-transfer capability and electrochemical activity of the HATN/rGO composite, suggesting its great potential as the additive material for high-performance corrosion protection.

Chemically-resistant epoxy novolac coatings: Effects of size-fractionated technical Kraft lignin particles as a structure-reinforcing component

To provide protection against corrosion in harsh environments, high performance anticorrosive coatings are applied on steel structures at all scales. However, to also limit the use of fossil-based ingredients, there is a growing demand to incorporate renewable raw materials in the coating formulations.In this study, to replace pigments and fillers of an epoxy novolac coating, technical Kraft lignin particles were ground and size fractionated (i.e., sieved), and used for formulation work. The effects of sieved and unsieved Kraft lignin, as structure-reinforcing components, on the anticorrosive and mechanical performance of epoxy coatings were subsequently investigated using the following methods: size exclusion chromatography (SEC), phosphorous nuclear magnetic resonance spectroscopy (31P NMR), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), salt spray exposure, pull-off, König pendulum hardness, and chemical resistance tests.Compared to the unsieved-lignin reference (U-L EN), the coating based on lignin fines (S-L EN) showed about 31 % lower rust creep after 70 days of salt spray exposure. However, no surface defects or chemical degradation were observed for any of the coatings.For the S-L EN coating, excellent adhesion strength (23 MPa) and impact resistance (0.49 N), relative to reference values of 17 and 13 MPa and 0.41 and 0.07 N for commercial and lignin-based diglycidyl ether bisphenol F (L-DGEBF) coatings, respectively, were measured.The addition of lignin particles did not influence the chemical resistance, the hardness, and the glass transition temperature of the epoxy novolac coatings.In summary, chemically unmodified Kraft lignin particles, after grinding and sieving, can be incorporated in epoxy novolac coatings (up to 25 vol%), thereby providing a bio-based alternative to pigments and fillers in heavy duty coatings (primers in particular).

Development of metal-organic framework (MOF) decorated graphene oxide/MgAl-layered double hydroxide coating via microstructural optimization for anti-corrosion micro-arc oxidation coatings of magnesium alloy

• GO/LDHs coating (G/LDHs) as a connecting carrier was prepared on the MAO coating. • ZIF-8 particles continuously grow symbiotically on G/LDHs coating (ZG/LDHs coating). • ZG/LDHs coating improves corrosion resistance of AZ31 alloys. • It is feasible to build high-performance anticorrosive coatings with MOF materials. An efficient and simple in-situ growth strategy has been discovered for the preparation of highly reproducible and continuous symbiotic ZIF-8-based anticorrosion coating by using graphene oxide (GO)/MgAl-NO 3 layered double hydroxides (G/LDHs) buffer layer as a new type of connecting carrier based on micro-arc oxide (MAO) coating of AZ31 magnesium alloy. The components of ZIF-8 were adsorbed and bounded to the surface of the G/LDHs buffer layer-modified substrates to promote the nucleation of ZIF-8, thus growing a phase-pure, uniform, and good symbiosis ZIF-8 membrane. ZIF-8 particles with different growth times compensate for the grain boundary defects of the G/LDHs coating precursor buffer layer to different degrees. The prepared ZIF-8-based coating has excellent stability and corrosion resistance. The results demonstrate that the G/LDHs buffer layer provides a new channel for the MOF-modified MAO substrate of AZ31 magnesium alloy. It also proves that it is feasible to build high-performance anticorrosive coatings with MOF materials.

Designing a Ti3C2Tx MXene with long-term antioxidant stability for high-performance anti-corrosion coatings

Two-dimensional titanium carbide (Ti3C2Tx) MXene has many distinctive advantages, including high conductivity, energy-storing, catalysis, etc. In particular, its accordion-like lamellar structure could provide excellent barrier properties to corrosive agents, which exhibit potential application value for anti-corrosion coatings. However, the problem that MXenes are susceptible to oxidative degradation in an aggressive environment limits its further application in the field of corrosion prevention. Herein, in our work for the first time, an effective method was developed for protecting sensitive Ti3C2Tx MXene against oxidation by imidazolium salt modification (I-Ti3C2Tx), which considerably increased MXene antioxidant stability. The crystalline structure of I-Ti3C2Tx remained unaltered in an aqueous solution for 30 days and kept the lamellar structure for a long period. Simultaneously, 1.0 wt% I-Ti3C2Tx/EP could provide excellent anti-corrosion protection. A new synergistic mechanism for improving antioxidant stability and anti-corrosion property of I-Ti3C2Tx/EP coatings was developed and clarified based on the free radical scavenging ability of imidazolium ions and the chemical characteristics of MXene.

Waterborne reduced graphene oxide dispersed sebacic acid modified soy epoxy nanocomposite: A green and sustainable approach for high performance mechanically robust anticorrosive coatings

The waterborne soy oil epoxy (WSOE) has attracted significant interest due to its eco-friendly and low or no volatile organic compounds (VOCs) being free. Further, it is one of the promising precursors used to formulate low-cost, eco-friendly, high-performance anti-corrosive coatings. Because of this, the present study reports the synthesis of waterborne soy epoxy and its nanocomposite coatings formulation using soy oil epoxy and sebacic acid as a modifier (a green bio-based precursor) and reduced graphene oxide (RGO) nanofillers. The sebacic acid was used to modify waterborne oleo epoxy through salt formation, making the epoxy more bio-compatible and environment-friendly. The structural characterization of these materials was performed using X-ray diffraction, proton and carbon thirteen-NMR, and Raman spectroscopies (XRD, FT-IR, 13CNMR, 1HNMR, Raman). The graphene-epoxy nanocomposite coatings have exhibited superior thermal, physicomechanical, and corrosion protective (impedance = 106 Ω cm2 and phase angle = 78o) properties. The potentiodynamic polarization and electrochemical impedance spectroscopy techniques were used to investigate the anticorrosive activities of nanocomposite and soy epoxy coatings. The physicomechanical studies on nanocomposite coatings have displayed excellent performance i.e. Impact resistance (150 lb./in.), scratch resistance (11 kg) and MEK tests (>400 cycles), and superior corrosion protective properties as compared to those of soy epoxy and other such reported coating systems.

High-performance anti-corrosive coatings based on rGO-SiO2-TiO2 ternary heterojunction nanocomposites for superior protection for mild steel specimens

Corrosion is the impairment of metal which typically generates the oxides of the original metal and results in a destruction of the surface and loss of mechanical properties like strength, ductility, impact strength so it is considered to be a serious issue. To regulate this, we have synthesized an anticorrosive ternary nanocomposite coating. We have prepared (GO/rGO-SiO2-TiO2) binary and ternary nanocomposite coating with incorporation of organic resin (Cashewnut resin). GO was derived from graphite powder by hummers method whereas rGO was obtained by the reduction process of GO. SiO2 and TiO2 were prepared by wet chemical process. The nanoparticles were subjected for its size, structural and morphological characterization. The nanoparticles are mixed with natural resin for building up of nanocomposites coating. The composite mixture was deposited on the mild steel panel and the coated panels were subjected to contact angle analysis, salt spray testing and electrochemical studies to analyse the hydrophobic, roughness, corrosion resistivity etc. The ternary composite coating rGO/SiO2/TiO2 shows high performance of corrosion resistivity, the corrosion rate obtained from anticorrosion study is 0.0187 mm/year after 152 h of immersion in aggressive saline environment, thus the nanocomposites coating exhibits high anticorrosion activity.

In Situ Polymerization to Boron Nitride-Fluorinated Poly Methacrylate Composites as Thin but Robust Anti-Corrosion Coatings

High-performance anti-corrosion coatings featuring easy processability and thin thickness are highly desired in industry. Yet, solution process coating often faces a sedimentation problem with particles which are used as reinforcement in coatings. In this contribution, boron nitride (BN) was modified by an acrylate silane coupling agent (KH-570) to obtain acrylated BN flakes. Afterwards, the acrylated BN flakes were in situ copolymerized with 2-(perfluorohexyl)ethyl methacrylate to synthesize BN-fluorinated poly methacrylate (PFBP) composites. The as-obtained PFBP composites can form stable coating solutions, in which sedimentation of BN flakes seldom happens. The coating solution can easily form uniform coatings on various substrates with nanoscale thickness, confirmed by scanning electron microscope (SEM). The corrosion resistance of the samples coated PFBP coatings in 3.5 wt.% sodium chloride solution was evaluated by electrochemical impedance spectroscopy (EIS). It is indicated that the incorporation of BN flakes greatly reduce the corrosion rate. Adhesion measurements and abrasion resistance test indicate the PFBP coating performs good adhesion to substrate and robustness. Through the in situ polymerization, acrylated BN flakes are connected with the polymer chain, which inhibits the sedimentation of BN in the coating solution. Additionally, the BN flakes dispersed in the fluorinated polymer act as barriers, improving the corrosion resistance of the coated samples.

Synergistic effect of polybenzoxazine/ZrO2 encapsulated polyurethane nanocomposite coatings for enhanced barrier properties of steel in seawater

PurposeThe purpose of this study is to use polybenzoxazine (Pbz) functionalized ZrO2 nanoparticles to synthesize polyurethane (PU)-PbZ/ZrO2 nanocomposite. The results derived from the electrochemical impedance spectroscopy (EIS) and polarization studies indicated the superior anticorrosive activity of PU-Pbz/ZrO2 nanocomposite coatings compared to those of plain PU coatings. The decreased corrosion current was detected on the scratch of the PU-Pbz/ZrO2 nanocomposite-coated mild steel surface by scanning electrochemical microscopy (SECM) compared to other studied coatings. The superior anticorrosive and mechanical properties of the proposed nanocomposite coatings provide a new horizon in the development of high-performance anticorrosive coatings for various industries.Design/methodology/approachThe Pbz functionalized ZrO2 nanoparticles were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and thermogravimetric analysis (TGA) in terms of the structural, morphological and thermal properties of these coatings. A different formulation of coatings such as PU, PU-Pbz, PU-ZrO2 and PU-Pbz/ZrO2 were prepared and investigated for their corrosion protection performance on mild steel in natural seawater by electrochemical techniques. The surface morphological studies were done by SEM/EDX and XRD analysis.FindingsThe superior anticorrosive property of the proposed nanocomposite coatings provides a new horizon in the development of high-performance anticorrosive coatings for various industries. Addition of Pbz wrapped ZrO2 nanoparticles into the PU coating resulted in the blockage of charge transfer at the metal/electrolyte interface, which reduced the dissolution of mild steel. It was revealed from the SEM/EDX analysis that the formation of the corrosion products at the metal/electrolyte interface behaved as the passive layer which reduced the dissolution of steel.Originality/valueThe inclusion of polybenzoxazine functionalized ZrO2 nanoparticles to the polyurethane coating reinforces the barrier and mechanical properties of PU-Pbz/ZrO2 nanocomposite, which is due to the synergistic effect of ZrO2 and Pbz.

Sulfonated polyaniline assisted hierarchical assembly of graphene-LDH nanohybrid for enhanced anticorrosion performance of waterborne epoxy coatings

The strong barrier of well dispersed graphene provides excellent labyrinth effect in organic coating. However, the high conductive graphene sheets are prone to forming conductive path in coating matrix with corrosive medium, resulting in serious micro current corrosion. Although a large number of methods to reduce the conductivity of graphene have been reported, how to balance the conductivity of graphene, the affinity between filler and resin, and the self-healing property of coating are major issues for researchers to consider. Here, we have developed a strategy for insulating graphene with layered double hydroxides via sulfonated polyaniline mediated self-assembly approach. Graphene sheets were stripped by sulfonated polyaniline to improve the interlayer spacing of graphene followed by covered with layered double metal hydroxide (LDH) via ionic crosslinking, which reduced the conductivity of graphene and improve the interfacial compatibility between the fillers and the resin. At the same time, the electroactive polyanilines between the graphene layers afford the coating with self-healing effect. The novel graphene-LDH nanohybrid material was incorporated into the waterborne epoxy resin to prepare corrosion resistant coatings with a thickness of about 70 ± 5 μm. The electrochemical and self-healing properties of the prepared composite coating were characterized by EIS, Tafel and LEIS techniques. This novel sulfonated polyaniline crosslinked graphene-LDH nanohybrid expands in the research and development of graphene based high performance anticorrosive coatings.

Ultrahigh anti-corrosion performance of polymer-based coating filled with a novel micro network nanofiller

Designing fillers for high-performance anti-corrosion coatings, especially coatings suitable for harsh environments, remains a huge challenge. Herein, a novel micro network nanofiller CNTs/LDH-MoO4 (CLM) was successfully obtained by a facile in-situ growth method and employed to endow coating with excellent anti-corrosion performance. Electrochemical impedance spectroscopy (EIS) demonstrated the low frequency impedance value of the CLM coating maintained above 1011 ohm·cm2 during the 60 days of immersion in 3.5 wt.% NaCl solution. Surprisingly, the coating still exhibited superior anti-corrosion performance after being immersed for 10 days in the harsh environment where 3 MPa pure oxygen and 3.5 wt.% NaCl solution coexist.

High protection performance of vanadium pentoxide-embedded polyfuran/epoxy coatings on mild steel

V2O5-incorporated polyfuran (PF) as nanofiller(V2O5-PF) was used to synthesize epoxy (EP)-PF/V2O5 nanocomposites. The PF-functionalized V2O5 nanoparticles were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The corrosion protection performance of these coatings on mild steel in natural seawater was determined by electrochemical measurements. Results from electrochemical techniques revealed the superior anticorrosive activity of nanocomposite coatings compared to those of plain epoxy coatings. The superior anticorrosive property of the proposed nanocomposite coatings provides a new horizon in the development of high-performance anticorrosive coatings for various industries. Incorporating PF-functionalized V2O5 nanoparticles into the epoxy coating ensued in the blockage of charge transfer at metal–electrolyte interface which hindered the dissolution of metal/alloy. Scanning electrochemical microscopic (SECM) studies detected lower corrosion current on the EP-PF/V2O5 nanocomposite coated mild steel surface. SEM/EDX analysis examined the corrosion products which acted as the passive layer that reduced the dissolution of steel. The inclusion of PF-functionalized V2O5 nanoparticles to EP improved the mechanical properties of the coated surface which complimented the electrochemical studies.

Superior to graphene: super-anticorrosive natural mica nanosheets.

Graphene has been generally considered to be the most ideal anticorrosive material based on its extraordinary impermeability, but tends in practical applications to promote metal corrosion because of its inherently high electrical conductivity. Mica nanosheets (MNSs), in contrast, display excellent electrical insulation properties, as well as excellent temperature stability and chemical durability, and show tremendous potential for protecting metals, and hence are a promising substitute for graphene. To date, however, there have been no reports about MNS-based anticorrosive coatings, since it is much more difficult to exfoliate high-quality MNSs than other layered materials. In this work, high-concentration (4.3 mg ml-1) ultrathin MNS (1-5 layers) dispersions were synthesized based on a facile and efficient hydrothermal exfoliation approach. Epoxy (EP) coatings were filled with the as-obtained MNSs to enhance the anticorrosion performance of the coatings, and their corrosion behaviors were studied systemically through a series of measurements. With the addition of only 0.4 wt% MNSs, the corrosion rate was observed to be reduced 6500 fold, and the coating impedance increased by four orders of magnitude compared with the blank EP coating. We believe that this method opens a novel avenue for developing high-performance anticorrosive coatings to replace graphene materials for metal protection.

Influence of carbon nanodots encapsulated polycarbazole hybrid on the corrosion inhibition performance of polyurethane nanocomposite coatings

Carbon nanodots encapsulated in a polycarbazole hybrid-dispersed polyurethane nanocomposite coating with new exciting perspectives for high-performance anticorrosive coatings are shown.

Vanadium Pentoxide-Enwrapped Polydiphenylamine/Polyurethane Nanocomposite: High-Performance Anticorrosive Coating.

Nanocomposite coatings with synergistic properties hold a potential in long-term corrosion protection for carbon steel. Polydiphenylamine (PDPA) and vanadium pentoxide (V2O5) have rarely been used as a corrosion inhibitor. Moreover, oleo polyurethanes are always demanded in the field of anticorrosive coatings. In view of this, we have synthesized safflower oil polyurethane (SFPU) and their nanocomposites using V2O5-enwrapped PDPA (V2O5-PDPA) as nanofiller. Fourier-transform infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis were used to characterize the structural, morphological, and thermal properties of these coatings. Corrosion resistance performance of these coatings in 5 wt % NaCl solution was determined by electrochemical measurements and salt spray tests. These studies exhibited very low Icorr (7.45 × 10-11 A cm-2), high Ecorr (-0.04 V), impedance (1.69 × 1011 Ω cm2), and phase angle (84°) after the exposure of 30 days. An immersion test, in 1 M H2SO4 solution for 24 h, was also performed to investigate the effect of oxidizing acid on the surface of coatings. These results revealed the superior anticorrosive activity of nanocomposite coatings compared to those of plain SFPU and other such reported systems. The superior anticorrosive property of the proposed nanocomposite coatings provides a new horizon in the development of high-performance anticorrosive coatings for various industries.

High Performance Anti-Corrosion Coatings of Poly (Vinyl Butyral) Composites with Poly N-(vinyl)pyrrole and Carbon Black Nanoparticles.

Zinc is widely used in battery negative electrodes and steel coatings for automotive industries. The anti-corrosion property of zinc is the most important factor determining the performance and lifetime of the products. In this paper, both size-controlled poly N-(vinyl)pyrrole (PNVPY) nanoparticles and carbon black (CB) nanoparticles were compounded with poly (vinyl butyral) (PVB) binder developing a series of composite coatings covered on the zinc substrates using a spin-coating technique. The morphologies of the surface and cross section of the PNVPY/CB/PVB coatings indicate that the PNVPY and CB nanoparticles are uniformly distributed in the matrix. The corrosion resistance of the composite coatings was tested by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization in a 3.5% NaCl solution. It is found that the coating with 1.9 wt.% PNVPY and 2.3 wt.% CB nanoparticles shows a remarkably high resistance value (Rc) and corrosion protection efficiency (99.99%). Meanwhile, the immersion results also reveal its superior corrosion resistance. It is considered that the nanoscale dispersion of PNVPY and carbon in PVB matrix and the strong interface action between the nanoparticles and PVB result in the uniform microstructure of the composites which endues the superior corrosion properties of the coatings.

Complete long-term corrosion protection with chemical vapor deposited graphene

Despite numerous reports regarding the potential of graphene for corrosion protection, examples of chemical vapor deposited (CVD) graphene-based anticorrosive coatings able to provide long-term protection (i.e. several months) of metals have so far been absent. Here, we present a polymer-graphene hybrid coating, comprising two single layers of CVD graphene sandwiched by three layers of polyvinyl butyral, which provides complete corrosion protection of commercial aluminum alloys even after 120 days of exposure to simulated seawater. The essential role played by graphene in the hybrid coating is evident when we compare the results from a polymer-only coating of the same thickness, which fails in protecting the metal after less than 30 days. With the emergence of commercially available large-area CVD graphene, our work demonstrates a straightforward approach towards high-performance anticorrosive coatings, which can be extended to other two-dimensional materials and polymers, for long-term protection of various relevant metals and alloys.

Insights into the Use of Metal-Organic Framework As High-Performance Anticorrosion Coatings.

Metal-organic frameworks (MOFs) have shown great potential in gas storage and separation, energy storage and conversion, vapor sensing, and catalysis. Nevertheless, rare attention has been paid to their anticorrosion performances. At present, substantial hydrophobic and water stable MOFs (like ZIF-8), which are potentially favorable for their applications in anticorrosion industry, have been successfully designed and prepared. In this study, a facile ligand-assisted conversion strategy was employed to fully convert ZnAl-CO3 layered double hydroxide (LDH) precursor buffer layers to well intergrown ZIF-8 coatings. DC Polarization tests indicated that prepared ZIF-8 coatings showed the corrosive current 4 orders of magnitude lower than that of bare Al substrates, demonstrating that MOF materials were superb candidates for high-performance anticorrosion coatings.

Synthesis of high-performance alkyd anticorrosion coatings based on waste poly(ethylene terephthalate)

Synthesis of high-performance anticorrosive coatings obtained from alkyd resins (ARs) based on waste poly(ethylene terephthalate) (PET) glycolyzates is presented. PET glycolyzates, synthesized by catalytic depolymerization with trimethylolpropane (TMP) and dipropylene glycol (DPG), were used as replacement of part of the polyhydroxylic component during the ARs synthesis. The obtained glycolyzates and ARs were analyzed using FT-IR and 1HNMR spectroscopy and acid, iodine, and hydroxyl value were determined. Thickness, adhesion, swelling, corrosion, spraying and layering of the synthesized ARs, as well as alkyd coating film were determined in accordance with SRPS EN ISO standards. ARs were produced in high yields and FT-IR and 1NMR analysis results confirmed assumed structures. All synthesized ARs show good elasticity, flexibility, adhesion and the gloss values are greater than 85 %, and the alkyd coating films based on AR1 and AR3 showed best corrosion results. The most effective dryer catalyst combination was 0.5 wt.% Ca, 0.03 wt.%, Co and 0.45 wt.% Zr.