Development of PU Coatings from Neem Oil Based Alkyds Prepared by the Monoglyceride Route

This work deals with the preparation of alkyd resins from neem oil and their utilization in preparation of polyurethane coatings. Alkyd resins were synthesized by reaction of neem oil monoglycerides with four different divalent acids like phthalic anhydride, maleic anhydride, itaconic acid, and dimer fatty acid. The alkyds formation was studied by determining the acid number of the reaction mixture at regular intervals of time and the extents of the polyesterification reactions were calculated during the formation of alkyds. The structures of synthesized alkyds were confirmed by FT‐IR and ¹H‐NMR spectroscopic analysis and also by end group analysis such as hydroxyl and acid values. The synthesized alkyds were reacted with TDI to prepare PU coatings and their performance was compared with PU coatings prepared from a commercial alkyd.     

Preparation and evaluation of linseed oil based alkyd paints

Alkyd resins are produced with reaction of oil or fatty oil, polyol and polyacid. Alkyd resins are commonly used in coating and paint industry due to ease of application in changing environmental conditions. Linseed oil based paints executed all requirements of technical properties, drying time, storage properties, simplicity in maintenance, appearance, economy, etc. In this study, linseed oil based alkyd resins having different oil contents were synthesized     

Design and synthesis of bio-based epoxidized alkyd resin for anti-corrosive coating application

Alkyd resins with long aliphatic chain in their backbone are not suitable for high-performance applications. To overcome this limitation of alkyd resins, their backbone structure is usually chemically modified. In this study, an alkyd resin was successfully synthesized from renewable resources, including itaconic acid and linseed oil. Subsequently, the unsaturated backbone of the alkyd resin was converted to oxirane ring through epoxidation reaction in the presence of hydrogen peroxide and acetic acid. The epoxidized alkyd (EA) resin backbone was modified with various amounts of 3-amino propyltrimethoxysilane (APTMS) from 10 to 40 mol percent to enhance the anti-corrosive properties of coatings prepared from the alkyd resins. The structural elucidation of synthesized resins was described by physicochemical analysis and Fourier transform infrared and ¹H nuclear magnetic resonance spectroscopies. The EA resin and APTMS-modified EA resin were cured by itaconic acid in 1:1 stoichiometric ratio on the equivalent weight basis. The differential scanning calorimetric and thermogravimetric analysis results showed that thermal properties improved with increasing APTMS content. The cured coatings were characterized for their mechanical properties, chemical and solvent resistance, gel content, and water absorption. The corrosion-resistance performance of coatings was evaluated by electrochemical impedance spectroscopy and salt-spray test. It was observed that the highly cross-linked structure of the APTMS-modified EA coatings enhanced the corrosion protective property of coating films.     

Effect of branching in hyperbranched alkyd on the performance of alkyd polyurethane coating

Hyperbranched alkyd was synthesized by single‐step approach using trimethylolpropane, mono pentaerythritol as core material, and 2,2‐bis(methylol)propionic acid (DMPA), a combination of dehydrated castor oil fatty acid and coconut oil fatty acid as chain extender. A series of hyperbranched alkyds were prepared at different degree of branching in the alkyd structures by changing the amount of DMPA in the alkyd resin formulation. The resins were characterized by Fourier transform infrared and ¹H‐nuclear magnetic resonance (NMR) spectroscopic technique. These hyperbranched alkyds were converted into polyurethane coating after reaction with hexamethylene diisocyanate trimer at a definite ratio in the presence of dibutyltin dilaurate as a catalyst. The effect of branching and polymeric chain entanglement on the glass transition temperature, T_g of the alkyd polyurethane coating (APUC) was studied by differential scanning calorimetry technique. The performance of such APUC in terms of gloss, gloss retention under accelerated QUV radiation, natural outdoor exposed condition, mechanical, and corrosion resistance properties were enhanced with the increase of polymeric chain entanglement, i.e., compactness or higher order of branching in the alkyd resin structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45835.     

Resins and additives for powder coatings and alkyd paints, based on renewable resources

Due to limited fossil resources and an increased need for environmentally friendly, sustainable technologies, the importance of using renewable feedstocks in the paint and coatings area will increase in the decades to come. This paper highlights some of the perspectives in this area. Alkyd resins for high-solid paints and reactive diluents, completely based on commercially available renewable resources, were prepared and characterized. Alkyd resins based on sucrose and unsaturated fatty acids or oils showed a low intrinsic viscosity, making them suitable to be used in high-solid alkyd paints. Reactive diluents based on similar starting materials showed excellent properties with regard to thinning behavior and effect on drying characteristics. Powder coating polyester resins were synthesized, starting from isosorbide and diacids. Polyester resins with glass transition temperatures up to 70°C were obtained. Incorporation of small amounts of other diols and trifunctional components was found to improve color and coating properties. In order to create completely renewable resin systems, the development of renewable drying agents for alkyds and crosslinkers for powder coatings is in progress. Presented at the XXVIII FATIPEC Congress, in Hungary, June 2006.     

Tall oil fatty acid mixtures as a new approach to quality alkyds

Conclusions Tall oil fatty acids may replace up to 50% of linseed or soya fatty acids, using the High Polymer Alkyd Technique, to obtain similar dry rates and resistances of conventional all-linseed or soy long-oil vehicles. Tall oil fatty acids also can be substituted for 25% of either linseed or soya fatty acids without adverse effects on the drying rates of conventionally prepared long-oil alkyds. Tall oil fatty acids likewise may be used in conjunction with the alcoholysis type of alkyds by the use of the High Polymer Technique. These vehicles show properties similar to conventional resins prepared from linseed oil and improvements over resins based on soybean oil.     

A Novel Type of Organo Clay Containing Alkyd-Melamine Formaldehyde Resins

In this study, organo clay-modified alkyd resins were synthesized and these modified alkyd resins were cured with different ratios of melamine formaldehyde resin for the first time. Alkyd resins were blended with 30% and 40% of a commercial melamine-formaldehyde resin. Alkyd-melamine formaldehyde resin films were cured at 140°C for 2 h in an oven. The effect of organo clay addition on the physical and chemical film properties was investigated. These surface coating properties of the resins enhanced with amount of organo clay up to 2–3%. These resins are suitable for manufacturing of high-performance industrial baking enamels.     

Preparation and curing of alkyd based on ricinoleic acid/melamine coatings

Three alkyd resins of high hydroxyl numbers based on ricinoleic acid, phthalic anhydride and glycerin, trimethylolpropane or ethoxylated pentaerythritol as polyol were prepared. Afterwards synthesized alkyds were made into baking enamels by blending with commercial melamine-formaldehyde resins (weight ratio of 70:30 based on dried mass). Alkyd/melamine resin mixtures were cured in a differential scanning calorimeter (DSC) under non-isothermal mode. Apparent degree of curing as a function of temperature was calculated from the curing enthalpies. Fourier transform infrared spectroscopy (FTIR) was used to identify characteristic peaks of resin mixtures before and after being cured. The gel content, hardness, elasticity and impact resistance of coated film cured at 150 °C for 60 min were measured. The onset of film thermal degradation, determined by thermogravimetric analysis (TGA) was observed at the temperatures from 281 to 330 °C. Based on the results obtained we suppose that the combinations of synthesized alkyds based on ricinoleic acid with used melamine resins could be employed as the compositions for the preparation of baking enamels.     

Synthesis and Characterization of Canola Oil Alkyd Resins Based on Novel Acrylic Monomer (ATBS)

A water-reducible alkyd resin was synthesized using the renewable resource canola oil and then chemically modified with styrene and the novel monomer acrylamido tertiary butane sulfonic acid (ATBS). Infrared spectroscopy and nuclear magnetic resonance techniques were used for structural elucidation of newly synthesized resins. Analyses of their physico-chemical and thermal properties revealed that styrene and ATBS-grafted water-reducible polymers have better thermal, chemical and coating properties than canola oil alkyd resins.     

Improving coating characteristics of palm stearin alkyd by modification with ketone resin

The present study describes the modification of long oil palm stearin based alkyd resin through blending it with a commercially available ketone resin to improve its coating characteristics. The effects of blending on air drying time, hardness, adhesion, gloss, impact strength, chemical resistance and thermal behavior of dried films of blends were investigated and compared to virgin alkyds. It was found that blending results in modifying coating characteristics of palm stearin based alkyd resins, significantly. Best result was observed for weight ratio 70:30 of alkyd and ketone resins.     

Novel renewable alkyd resins based on imide structures

New bio-based building blocks were synthesized from amino acids like lysine, glycine, and phenylalanine and from di- or tricarboxylic acids like succinic acid and citric acid, respectively. These building blocks were incorporated into alkyd resins by standard polycondensation chemistry and technology. The resulting alkyd resins were evaluated as coating resins, either by casting films from xylene or by making coatings from water-based alkyds after emulsification of the synthesized alkyd resins. The renewability content of the resins could easily be varied between 80 and ca. 95 wt%. The properties of the highly bio-based coatings look promising, some even outperforming standard commercial alkyd resins.     

The effect of alkyd resins on the properties of AA‐NC semi‐IPNs as binders in wood finish

Wood coatings of AA‐NC semi‐interpenetrating polymer networks (semi‐IPNs), made from acid curing amino‐alkyd resins (AA) and nitrocellulose (NC), were prepared by sequential polymerization method. To investigate the effects of oil length on the properties of AA‐NC semi‐IPNs, three grades of alkyd resins (Alkyd) containing 38, 48, and 58% oil were synthesized with phthalic anhydride, glycerol, and soybean oil, employing alcoholysis method. The butylated urea formaldehyde resin (UF) and melamine formaldehyde resin (MF) were also prepared in this study. The AA‐NC semi‐IPNs were maintained at a weight ratio of AA : NC of 25 : 75, where the AA was the composition of MF : UF : Alkyd of 7.5 : 22.5 : 70 (by weight), and 10% of p‐toluene sulfonic acid solution (concentration, 25% in isopropyl alcohol) based on the weight of amino resins was added as acid catalyst. The properties of coatings such as viscosity, drying time, and gel time, and the properties of films including adhesion, hardness, abrasion resistance, impact resistance, tensile strength, released formaldehyde, lightfastness, solvent resistance, and durability were examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1923–1927, 2004     

The use of aminolysis,aminoglycolysis, and simultaneous aminolysis–hydrolysis products of waste PET for production of paint binder

This work is concerned with the use of aminolysis, aminoglycolysis, and simultaneous aminolysis–hydrolysis products of waste PET for production of paint binder based on alkyd resin. For this purpose, first, aminolysis, aminoglycolysis, and simultaneous hydrolysis–aminolysis reactions of waste PET were carried out in the presence of different chemical agents in xylene medium at high pressures. Reactions of waste PET flakes obtained from grinding postconsumer water bottles were carried out in an autoclave at higher temperatures. Then, four alkyd resins, formulated to have oil content 40–50%, were prepared using these depolymerization products. One of resins is “reference alkyd resin” which was prepared by using soybean oil fatty acid, phthalic anhydride, glycerine, and ethylene glycol for comparison. Other three alkyds are “depolymerization product‐based alkyd resins” in which depolymerization products is used instead of ethylene glycol. Then, the physical and chemical surface coating properties and thermal behaviors of alkyd resins films were investigated comparatively. As a result, we concluded that aminolysis, aminoglycolysis, and simultaneous aminolysis‐hydrolysis products of waste PET are suitable for manufacturing both air drying and oven curing paint binder based on alkyd resins. The film prepared from alkyd resin based on simultaneous aminolysis‐hydrolysis product showed extremely good surface coating properties and thermal stability. POLYM. ENG. SCI., 54:2272–2281, 2014. © 2013 Society of Plastics Engineers     

Waterborne Coatings Based on Renewable Oil Resources: an Overview

Polyurethane dispersions are gaining in importance due to their environmentally friendly coating system, versatile coating properties and ease of application. An enormous amount of research is focused on waterborne coatings such as waterborne alkyds, water-reducible alkyds, alkyd–acrylic hybrids, oil modified polyurethane dispersions and their composite latexes. This review gives a comprehensive compilation of recent studies on the synthesis and applications of waterborne coatings. The article specifically covers all of the research work carried out in the field of waterborne alkyd–acrylics, polyurethane dispersions and their hybrid latexes systematically.     

Factors influencing the stability and film properties of acrylic/alkyd water-reducible hybrid systems using a response surface technique

Acrylic-grafted-alkyd resins were prepared by free radical chemistry. Long, medium, and short oil alkyds were prepared using soybean oil, glycerol, phthalic anhydride (PA), and tetrahydrophthalic anhydride (THPA) and used as the alkyd phase. Acrylic co-monomer formulas containing methyl methacrylate (MMA), butyl acrylate (BA), methacrylic acid (MAA), and vinyl trimethoxysilane (VTMS) were polymerized in the presence of the different alkyds using 2,2′-azobisisobutyronitrile (AIBN) as the initiator to obtain the final grafted structures. Design of experiments was used to understand how different variables in the synthesis of the acrylated-alkyds affect the film performance. A Box–Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic–alkyd hybrid resins were reduced with an amine/water mixture. The hydrolytic stability of hybrid alkyd dispersed in water was evaluated. Cured films were prepared and basic coatings properties were also evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. The hydrolytic stability was dependent on the acrylic to alkyd ratio. The oil length of the alkyd backbone had a minimal effect on stability of the resin and film performance.     

Preparation and characterization of water reducible alkyd resin/colloidal silica nanocomposite coatings

In this study, water reducible alkyd resins containing different amounts of colloidal silica were synthesized for the first time. In order to achieve this, alkyd resin, which has an oil content of 35%, was prepared with tall oil fatty acid, isophthalic acid, trimellitic anhydride, and trimethylolpropane. The alkyd resin was neutralized with triethylamine, and was dissolved in an isobutyl alcohol-isopropyl alcohol-butyl glycol mixture to produce 75% (wt.) solution, which was called stock alkyd resin. The stock alkyd resin was diluted with water to 50% (wt.) concentration with water and colloidal silica mixture in order to prepare an alkyd solution containing 0%, 5%, 10%, 15% and 20% colloidal silica. Then the effect of the silica nanoparticle addition on the surface coating properties, thermal behaviors and surface morphologies of water reducible alkyd resins was investigated. As a result, the addition of colloidal silica has improved surface coating properties and thermal behaviors of nanocomposite water reducible alkyd resin.     

Offset printing inks based on rapeseed and sunflower oil. Part I: Synthesis and characterization of rapeseed oil-and sunflower oil-modified alkyd resins

Two sets of alkyd resins of variable oil lengths with the required properties for offset printing ink formulations, modified by sunflower and rapeseed oil, were synthetized according to the “monoglyceride” process. The influence of the acyl composition of the modifying vegetable oil and of the oil content on alkyds’ properties was determined by detailed chemical and rheological characterization. Molecular structure, size, and molecule size distribution appeared to be linked to these two factors. A comparative study with two usual linseed oil-modified alkyds led to determination of the more appropriate alkyds for applications in offset varnishes.     

水分散型醇酸树脂的合成及性能研究

以脂肪油、邻苯二甲酸酐、偏苯三酸酐和三羟甲基丙烷为主要原料合成了水分散性醇酸树脂。以原料中酸酐的比例为基础设计了合成配方,讨论了合成工艺、脂肪油的种类和比例以及醇解催化剂对水分散性醇酸树脂性能的影响。     

Effects of urea formaldehyde resin to film properties of alkyd–melamine formaldehyde resins containing organo clay

Organo clay modified alkyd resins were prepared and these modified alkyd resins were cured with different ratios of melamine formaldehyde and urea formaldehyde resins in this work. Alkyds formulated to have oil content 40% were prepared with phthalic anhydride (PA), glycerine (G), coconut oil fatty acid (COFA), dipropylene glycol (DPG) and organo clay. “K alkyd constant system” was used for the formulation calculations of the alkyd resins. Alkyd resins were blended with 40% of a commercial melamine formaldehyde. The films of the alkyd–amino resins were prepared from 60% solid content xylene solutions using 50 μm applicators. After the films were cured at 140 °C for 2 h in an oven, properties of the films were determined. The film properties of the alkyd–amino resins such as drying degree, hardness, adhesion strength, abrasion resistance, water, acid, alkaline, solvent resistance, and resistance to environmental conditions were investigated. The addition of the urea formaldehyde resin and organo clay has positive effect on the physical and chemical resistance of the alkyd–amino resins.     

Effects of oil type on the properties of short oil alkyd coating materials

Short-oil alkyd resins were prepared by using five different oil types: corn oil, rice bran oil, sunflower oil, soya bean oil and dehydrated castor oil (DCO). Among these, soya bean oil gave alkyd resin with the darkest color because oxidation occurred. Auto air-dried coating films were developed and it was shown that film prepared from rice bran oil-based alkyd exhibited the longest drying time due to the low number of double bonds compared to other and the extra natural antioxidant in rice bran oil. DCO alkyd-based film revealed the shortest drying time, the greatest hardness but the poorest alkali and sea-water resistance. This is caused by the differences in the type of fatty acid and double bonds, the high amount of double bonds being in DCO. In addition, an increase in the reaction temperature only had an influence on darkening the alkyd color and decreasing the drying time of coating films. In terms of technical properties and cost competitiveness, soya bean oil-based film is the best. Coating films derived from all oil-based alkyds, except DCO, look promising for use in surfboard manufacturing.