Alkyd Coatings Research Articles

A wide range of modified alkyd resins based on a new source of dicarboxylic acid as a binder for anticorrosive paint

Purpose This paper aims to prepare alkyd protective paint by using modified alkyd with 3,6-dichloro benzo[b]thiophene-2-carbonyl glutamic acid (DCBTGA) as a source of dicarboxylic acid and evaluating their anticorrosive properties compared with those of unmodified alkyd coatings for steel protection. Design/methodology/approach Short, medium and long oil alkyds, which represented as (0, 10, 20 and 30% excess-OH) according to the resin constants (Patton, 1962), were prepared through a condensation polymerization reaction via a solvent process in a one-step reaction. The modification of alkyd was carried out by using DCBTGA as a source of dicarboxylic acid. The prepared modified alkyd was confirmed by IR and NMR spectral analysis. The physicochemical, mechanical and anticorrosion performance properties of the considered modified coating formulations against unmodified blank coating were studied to confirm their application efficiency. Findings The best results in terms of physicochemical, mechanical and anticorrosion performance properties were found according to the following of this order activity: 30 replacements of the modifier (DCBTGA) for each hydroxyl continent were 30% Ex-OH > 20% Ex-OH > 10% Ex-OH > 0% Ex-OH, compared with that formulation containing unmodified alkyd, especially with increasing the modifier percent. Originality/value The prepared DCBTGA-modified resins can be used for different applications based on the type of alkyd and application.

Conversion of Contaminated Post-Consumer Polyethylene Terephthalate into a Thermoset Alkyd Coating Using Biosourced Monomers.

The synthesis of a high-performance oxidative cross-linked thermoset alkyd coating is described that utilizes a novel recycling strategy from contaminated postconsumer waste polyethylene terephthalate (wPET). A single-stage "depolymerization-repolymerization" process has been developed that allows the exploitation of a waste stream from a commercial PET recycling process with 95% efficiency, which, when copolymerized with glycerol and tall oil fatty acid, delivers a sustainable fatty acid-functional polyester suitable for use in thermoset alkyd coatings. Physical drying challenges have been tackled via the development of a convergent polymer formulation strategy from a single source of wPET and the formulation of the resulting fatty acid-functional polymers with commercial alkyd driers, delivering a thermoset alkyd coating suitable for industrial applications.

Study on Adhesive and Microstructure Properties of Rice Husk Ash-Based Geopolymer Hybrid Alkyd Coating

ABSTRACT Ensuring strong adhesion, especially under varying environmental conditions, is a significant challenge in the field of coating technology. This research aims to enhance alkyd paint adhesive strength by incorporating rice husk ash-based geopolymer (GP-RHA) as a filler. Response Surface Methodology (RSM) technique was employed to systematically study the impact of GP-RHA levels on the adhesive strength of alkyd coatings under dry and wet conditions. The morphology of the coatings was analyzed using SEM-EDX. In dry pull-off test, the incorporation of GP-RHA in alkyd coatings led to an improvement in adhesive strength with the highest recorded adhesive strength of 3.9 MPa at a ratio of 41.67% wt. GP-RHA and 58.33% wt. alkyd paint. However, this higher proportion of GP-RHA resulted in the formation of a larger pore sizes hybrid coating, further causing water infiltration into the coating’s pore structure in wet pull-off test. Outcomes of this research showed the promising potential of GP-RHA filler in alkyd paint formulations to enhance adhesion. These findings offer valuable insights into the development of coatings utilizing agro-waste as a filler to improve its adhesive properties.

Aging of Environmentally Friendly Alkyd Coating Containing Tinuvin 292 under Effect of UV Radiation

This study presents durability of environmentally friendly alkyd coating containing Tinuvin 292 (a liquid hindered amine light stabilizer) under UV-thermo-humidity condition. Coatings were accelerated under UV-thermo-humidity complex for 100 cycles. FT-IR, TGA and SEM were used to value the changes of before and after accelerated weathering tested coatings. Results showed that gloss loss, adhesion, flexural strength, impact resistance, relative hardness of tested coating were much improved with 1.5 weight percent (wt.%) of Tinuvin 292. FT-IR spectrums of initial and aged coatings without Tinuvin 292 illustrated the significant changes on intensity of CH2 and C=O (ester) groups. Meanwhile, coating with Tinuvin 292 exhibited that intensity of CH2 and ester groups had been changed slightly. SEM images indicated that surface morphology of samples changed differently depending on the presence Tinuvin 292. After aging process, surface of aged coating without Tinuvin 292 became worse than that of coating with Tinuvin 292. TGA also showed that 1.5 wt.% of Tinuvin 292 had improved thermo oxidation stability of environmentally friendly coating.

MODIFICATION OF VEGETABLE OILS WITH REACTIVE COMPOUNDS FOR THE PRODUCTION OF PRINTING INKS

The modification of existing paints and varnishes based on alkyd resins, as well as the creation of new film formers using functionalised oligomers to improve the properties of materials in use, has been carried out. The aim of the work is to study vegetable oils used in the production of printing inks and to modify them in order to improve their technological properties. The work carried out allows the use of printing inks based on modified vegetable oils, with the expansion of their scope of application in the production of various printed products. The modification of vegetable oils was carried out by interaction with synthesised urethane-containing reactive block copolymers. Modification of mustard oil allows to change its structure, to increase its molecular weight by oligomerisation of the oil with obtaining of branched structure. Modified vegetable oils provide fast drying alkyd coatings, even in air. The properties of modified oils, the rate of film formation depend on the chemical nature of the block copolymer, its reactivity. The main processes of oil film structuring are due to oxidative and thermal polymerisation of double bonds of fatty acid residues. Optimisation of the vegetable oil modification process has been carried out, a formulation for the production of printing inks has been developed and production tests have been carried out with positive results.

Utilization of liquid epoxidized natural rubber as prepolymer and crosslinker in development of UV-curable palm oil-based alkyd coating

Innovation of new products from renewable resources are important for sustainable development. In this work, novel rubber-integrated palm oil-based alkyd resins were prepared using palm oil, glycerol, diacids, and liquid epoxidized natural rubber (LENR50). The synthesis started with alcoholysis of glycerol by palm oil to produce predominant mixture of monoglycerides, followed by polycondensation with diacids to form alkyd chain. In addition to glycerol, LENR50 was introduced as bio-based polyol for the alkyd synthesis. The rubber prepolymer was chemically integrated into the alkyd chain via the reaction between its epoxide or hydroxyl groups with COOH of diacids during polycondensation. Resultant alkyds were mixed with reactive diluent (styrene), crosslinker (trimethylolpropane triacrylate) and photoinitiators (benzophenone and 1-hydroxycyclohexyl phenyl ketone), and the mixtures were cured under UV irradiation. Introduction of LENR50 into the coating formulation has reduced the curing time, as well as improved some of the film properties of the coatings. Some of the LENR50-based coatings required as short as 3 mins of UV irradiation to form dry-hard films, while the control samples required much longer time. There was also notable increase in the gel content of the LENR-based alkyd coating, suggesting that the polyfunctionality of LENR50 could have increased the extent of crosslinking in the cured film. Other improvement recorded includes pencil hardness, film adhesion, solvent resistance, water resistance, and corrosion resistance. Thermal stability of the alkyd coatings is also reasonably good for general purpose coating applications. The findings from this study suggest that LENR50 could serve as an alternative polyol in synthesis of bio-based polyester binder for surface coating.

HydroxyUrethane Modifiers (HUM): An environmentally-friendly route to improve chemical resistance of alkyd coatings

This article highlighted the first synthesis of HydroxyUrethane modified alkyd resins by polycondensation reaction. Two new hydroxyurethane modifiers (HUM), with two hydroxyl functions, have been synthetized from renewable resources and have been copolymerized with alcohols and acid derivatives to yield HydroxyUrethane modified alkyd resins. Chemical resistance analysis has shown that HUM increased the alkali resistance of alkyd resins up to 44 %. Film properties such as gloss or drying time remained equivalent with the exception of color. Moreover, the increased flexibility of the films could be interestingly modified according to the structure of the HUM (aromatic or aliphatic). This result highlights a simple, greener and less toxic solution to improve the chemical resistance of alkyd resins.

Enhancing performance and sustainability in alkyd coatings with high-performance catalysts

Enhancing performance and sustainability in alkyd coatings with high-performance catalysts

Triple Benefits of Cardanol as Chain Stopper, Flame Retardant and Reactive Diluent for Greener Alkyd Coating

Cardanol, a waste from the food industry and widely produced (1 Mt/y), has been used as a chain stopper during the polycondensation of short oil alkyd resins in order to replace benzoic acid. Then, phosphorylated cardanol has been added in order to both reduce solvent content and bring flame-retardant (FR) properties to the alkyd resins. The renewable carbon content of the formulations has been increased up to 23%. The impact of the introduction of phosphorylated cardanol molecules on the drying time and flexibility has been studied as well as the thermal and flame-retardant properties by differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. The most effective flame-retardant coating that was associated with excellent FR properties and excellent coating properties has been obtained with phosphate-cardanol added at 2%wt of P. Indeed, the film properties were closed to the classical alkyd resin, the solvent content was reduced by 50% and the pHRR decreased by 42% compared to the reference alkyd resin.

Cardanol-modified alkyd resins: novel route to make greener alkyd coatings

Novel alkyd resins have been synthetized with mono- and di- functional cardanol monomers. This study has demonstrated that those monomers could replace some of the monomers used in alkyd resins, which were petrosourced. Indeed, the renewable carbon content have been increased by up to 12 %. The film properties (gloss, adhesion, drying time) have been investigated and the results showed that the introduction of cardanol monomers did not impact the coatings properties except for the color. Furthermore, thermogravimetric analysis has demonstrated that cardanol highly increased the thermal stability of alkyd resins.

Enhanced near-infrared reflectance and functional characteristics of nano metal oxide embedded alkyd coatings

The main idea of the research is to formulate alkyd based smart coatings with high NIR-reflectance to decrease the cooling load in order to maintain cool comfort in buildings. In addition to the NIR reflectance studies, the physical characteristics of the coating such as glossiness, hiding power, spreading area, volatile organic contents are evaluated. Heat reflective coatings are prepared by ball milling technique utilizing white metal oxide nanoparticles (NPs) titanium oxide (TiO2), zinc oxide (ZnO) and zirconium oxide (ZrO2) as pigments. The x-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) results reveal the prepared metal oxide pigments are of high purity. Bonding interaction between the alkyd resin and the NPs are studied using Fourier transform infrared spectroscopy (FTIR).The spectral reflectance of the prepared coatings are measured using spectrophotometer in the solar spectrum range, wherein ZnO based nanocoatings shows better results. The cool comfort is measured for ZnO nanocoatings in an enclosed glass cabinet and the differences in temperature with respect to exposure to sunlight are highlighted. Finally, a prototype coated with ZnO NPs maintains lower indoor temperature than the commercially available white paint coated model in the order of 2.7 °C.

Improvement of Environmentally-Friendly Alkyd Composite Coating with Graphene Oxide

In this article, environmentally-friendly alkyd coatings with different graphene oxide (GO) content of 0-1.5 weight percent (wt. %) were prepared for improving mechanical properties, corrosion protection and thermal oxidation resistance of coatings. GO in the coating was characterized by FT-IR. The corrosion resistance of environmentally- friendly alkyd coatings containing GO was investigated by salt fog testing. Effects of GO content on adhesion, flexural strength, relative hardness and thermal oxidation stability of alkyd coatings with and without GO were also examined. GO with the content of 1.2 wt. % significantly improved mechanical properties, corrosion resistance, thermal oxidation resistance of environmentally-friendly alkyd coatings.

Maleated soybean oil derivatives as versatile reactive diluents: Synthesis, characterization, and evaluation

AbstractFour maleated soybean oil (SBO) derivatives were synthesized and used as bio‐based reactive diluents (RDs) for alkyd coating systems. The RDs were prepared in a two‐step fashion: (a) Maleation of SBO with maleic anhydride (MA) via an ene reaction followed by (b) a nucleophilic acyl substitution of the grafted succinic anhydride with allyl‐ or methacrylate‐functional molecules. The structures were characterized using 1H NMR, 13C NMR, 13C‐1H heteronuclear single quantum coherence NMR, 13C‐1H heteronuclear multiple bond correlation NMR spectroscopy, FT‐IR (ATR) spectroscopy, and MALDI‐ToF‐MS. The 2D NMR spectroscopy techniques helped confirm that MA was successfully grafted onto SBO. FT‐IR spectroscopy identified new absorption bands at 1780 and 1850 cm−1, following the maleation reaction, corresponding to the anhydride functionality. Alkyd coating formulations were prepared with either 0, 10, 20, or 30 wt% of the different RDs. Brookfield viscosity measurements were conducted on the formulations to measure the efficiency of the SBO‐based RDs. At 20 wt% loading level, the RDs typically reduced the viscosity of the base alkyd resin by 50%–60%. Coatings tests and gel content measurements were also conducted in order to understand the effects that these RDs had on the performance of the alkyd coatings.

Preparation of excellent-water-resistance water-borne alkyd/acrylic hybrid coatings with varied maleic anhydride content

Water-borne alkyd/acrylic hybrid resins with varied maleic anhydride (MA) content were synthesized from the reaction between alkyd intermediate (AK) and maleic anhydride modified acrylic prepolymer (AC) followed by neutralization of carboxyl groups with triethylamine. Water-borne alkyd/acrylic hybrid resins were characterized by nuclear magnetic resonance (NMR), infrared spectrum (IR), transmission electron microscope (TEM), gel permeation chromatography (GPC), laser diffraction particle size analyzer, rheometer and thermogravimetric analysis (TGA). In addition, air-drying water-borne coatings were prepared using the above-mentioned dispersions and their coatings properties were evaluated. The results showed that the microstructure of the water-borne alkyd/acrylic hybrid dispersion was loose cotton type, which induced the accessibility of fatty acid chains to oxygen is unimpeded, therefore, higher cross-linking density would be obtained and resulted in the coating with optimum MA content exhibited excellent physical properties and water resistance, up to 32 days, which is better than the water resistance of all water-borne alkyd coatings or modified water-borne alkyd coatings reported up to now, and also better than the water resistance of the commercial water-borne alkyd/acrylic hybrid coating.

Effect of humidity on curing of alkoxysilane-functionalized alkyd coatings

Effect of humidity on curing of alkoxysilane-functionalized alkyd coatings

Polyaniline modified attapulgite incorporated in alkyd paint for carbon steel corrosion inhibition

ABSTRACT In the present work, polyaniline (PANI) modified attapulgite (ATP) nanocomposite was synthesized and employed as reinforcements to enhance the corrosion resistance of the alkyd coating. The morphological and structural properties of the synthesized ATP/PANI were characterized by transmission scanning electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Electrochemical impedance spectroscopy (EIS) was employed to investigate the corrosion protection performance of the alkyd coatings, showing the improved corrosion resistance in the presence of the ATP/PANI nanocomposite. Scanning Kelvin probe (SKP) and Raman spectroscopy were performed to characterize the metal passivation inhibition ability of composite coatings. Compared with blank coating, the SKP results revealed a clear decrease in electrochemical activity at the scratch of ATP/PANI coating. Results from Raman spectrum indicated that the protective capability of the scratched coating can be recovered through the passivation of polyaniline to form stable oxide film (Fe2O3) on metal surface.

The Impact of Fungicides, Plasma, UV-Additives and Weathering on the Adhesion Strength of Acrylic and Alkyd Coatings to the Norway Spruce Wood

The adhesion strength between the transparent acrylic or alkyd coatings and the Norway spruce (Picea abies Karst L.) wood was determined by EN ISO 4624 and analyzed concerning four variables: (a) fungicidal pre-treatment of wood with boric acid or benzalkonium chloride, (b) cold plasma modification of wood surfaces, (c) presence of hindered amine light stabilizer (HALS) or hydroxyphenyl-benzotriazoles (BTZ) in the role of UV-additives in coatings, and (d) weathering of coated wood—lasting 1 week in Xenotest by a modified EN 927-6, or 14, 28 and 42 weeks outdoors at 45° by EN 927-3. In the un-weathered state, the adhesion strength was positively affected by the initial plasma modification of wood surfaces, more evident with the application of acrylic water-borne coatings. On the contrary, the adhesion strength was not influenced by the fungicidal pre-treatment of wood and by the UV-additive’s presence in coatings. The adhesion was negatively affected by weathering—exponentially outdoor—irrespective of the fungicidal pre-treatment of wood, the plasma modification of wood surfaces, the coating type, and the presence of UV-additive in coatings.

Protective Properties of Alkyd Coatings Inhibited by Complex Zeolite-Phosphate Pigment

We study a complex anticorrosion pigment based on calcium-containing zeolite with zinc phosphate precipitated on its nanoporous surface. It is discovered that this pigment efficiently retards corrosion in an aluminum alloy placed in a synthetic acid medium and inhibits the subfilm corrosion of the metal near defects of the alkyd paint coating. The proposed pigment may serve as a promising inhibiting component of paint coatings aimed at the protection of structures made of aluminum alloy in the industrial atmosphere.

Effect of polyalcohols on the anticorrosive behaviour of alkyd coatings prepared with drying oils

Alkyd paints contain resins derived from vegetable oils. Alkyd resins have regained their importance since they are mostly composed of bio-based constituents recovered from biofuels production and agro-industrial waste. The anticorrosive performance of medium alkyd paints modified with Sacha inchi and linseed oils, and different ratios of glycerol and pentaerythritol, were compared by accelerated corrosion tests (Salt Fog and Sulphur Dioxide tests). This study focuses on comparing the effect of polyalcohol and oil type on physicochemical properties of resin solutions and cured films, and consequently, on the anticorrosive behaviour of paints prepared with the resins under study. Results showed that the mixture of pentaerythritol and Sacha inchi oil improves alkyd resin properties and enhance the anticorrosive performance of alkyd paints in accelerated weathering tests.

Visible light cure packages for improved drying kinetics in alkyd coatings

A solventborne linseed oil alkyd was formulated with two different free radical photo-initiators and a photosensitizer to enhance autoxidative crosslinking. Irgacure 784 and Irgacure 819 significantly decreased the dry-to-touch and through-cure times of alkyd systems at ambient conditions using indoor lighting. Real-time Fourier transform infrared spectroscopy, and solid state 13C NMR were used to monitor the curing process and two mechanisms are proposed to explain the increase in crosslinking. Films were evaluated for tensile, viscoelastic, and thermal properties, indicating an increase in crosslink density. Coating performance was evaluated, significantly increasing film hardness, while maintaining appearance. However, the adhesion and chemical resistance decreased. Visible-light curable alkyds offer excellent appearance and fast curing rates, without the use of cobalt driers.