Rubber seed oil modified with maleic anhydride and fumaric acid and their alkyd resins as binders in water‐reducible coatings

Rubber seed oil (RSO) was modified with different amounts of maleic anhydride, and RSO alkyds (50% oil length) were modified to various extents by the incorporation of different amounts of maleic anhydride and fumaric acid. All the resins were evaluated as water‐reducible binders. Modification with maleic anhydride increased the acid and saponification values of RSO but reduced the iodine value. RSO modified with maleic anhydride exhibited lower amounts of volatile organic compounds (<20 g/L) than the corresponding RSO alkyds (34–87 g/L). The alkyd samples were superior to the modified RSO in chemical resistance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3256–3259, 2003     

Synthesis and molecular weight characterization of rubber seed oil‐modified alkyd resins

Alkyd resins of 40% (I), 50% (II), and 60% (III) oil length (OL) were prepared with rubber seed oil (RSO), phthalic anhydride (PA), and glycerol (GLY), employing the two‐stage alcoholysis method. Changes in the physical characteristics of the reaction medium were monitored by determination of the acid value and the number‐average molecular weight, M_n , of in‐process samples withdrawn at different stages of the reaction. The mode of variation of these properties denotes that the preparation of RSO alkyds is complex. Molecular weight averages and the molecular weight distribution (MWD) of the finished alkyds were determined by GPC, cryoscopy, and end‐group analysis. Molecular weight averages and the MWD vary with differences in the formulation, with sample II exhibiting the narrowest size distribution. Values of M_n with the corresponding polydispersities in brackets are 3234 (1.91), 1379 (1.56), and 3304 (2.56) for samples I, II, and III respectively. M_n values obtained by cryoscopy are comparable to those obtained by gel permeation chromatography (GPC), while end‐group analysis seems to grossly overestimate their molecular weights. Correlation of M_n and the MWD with the quality of the finished alkyds shows that the narrower the size distribution the better the quality of the alkyd. Properties such as the rate of drying and resistance of the alkyds are optimum at 50% OL. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2431–2438, 2001     

Studies on the preparation of Parinari polyandra benth seed oil alkyd resins

Parinari polyandra Benth seed oil was utilized in the preparation of four sets of alkyd resin (35%, 50%, 60%, and 75% oil formulations) using a two‐stage alcoholysis‐polyesterification method. The rate of polyesterification was depended on the amount of oil used during synthesis. The properties of the alkyds (drying times, film characteristics, water and acid resistances, and solubility) were evaluated using relevant standards. Inclusion of cobalt naphthenate drier in the alkyds and their exposure to outdoor temperature improved the drying properties. White gloss paints formulated from the alkyds, considering a pigment‐volume concentration of 20.67% in the gloss paint formulation compare well with commercial standard. FTIR and ¹H‐NMR analysis confirm the alkyd (glycerol‐phthalate) structure. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of karawila (Momordica charantia) seed oil on synthesizing the alkyd resins based on soya bean (Glycine max) oil

Air drying long oil alkyd resins of 65% oil length were synthesized from a blend of soya bean (Glycine max) oil and karawila (Momordica charantia) seed oil. Different proportions of karawila seed oil (w/w% 10, 20, 30, 40 and 50) were blended with soya bean oil to examine the effect of karawila seed oil on the drying behavior of alkyds synthesized from soya bean oil. A sharp variation of viscosity is only observed for alkyd resins having more than 40% (w/w) of karawila seed oil. The polyesterification time was reduced and correspondingly the extent of polymerization was also reduced up to 30% (w/w). Significant variation in transesterification time was also observed for 30% (w/w). However, further increase in karawila seed oil above 40% (w/w) had only a marginal effect on the polyesterification reaction. The drying properties of the alkyd resins had been significantly improved with the increase of karawila seed oil up to 30% (w/w) but further increase in karawila seed oil resulted in poor drying characteristics. The film properties (drying time, hardness, adhesion, chemical resistance and gloss) of the alkyd resins were determined. The optimum film properties were recorded for the oil blend with 30% (w/w) karawila seed oil and 70% (w/w) soya bean oil.     

Synthesis and characterisation of chlorinated rubber seed oil alkyd resins

Rubber seed oil alkyd resins of 50% oil length were prepared (sample I) and parts of it modified by direct chlorination for 30 min (sample II), 60 min (sample III) and 90 min (sample IV). The concentration of the chloride ions was found to be 0.231, 0.236 and 0.239 mol/dm³ for samples II, III and IV, respectively. The IR spectra of the samples show that chlorine enters only into the aliphatic portion of the alkyd chain by addition. The physico-chemical properties and performance characteristics of the chlorinated and unchlorinated alkyd resins were determined. The results show that the chlorinated resins are fire retardant and that they possess superior drying properties, than the unchlorinated alkyds.     

Preparation and properties of urethane alkyd based on a castor oil/jatropha oil mixture

Castor oil is the only major natural vegetable oil that contains a hydroxyl group and so it is widely used in many chemical industries, especially in the production of polyurethanes. In this work, castor oil was interesterified with jatropha oil and the product was subsequently reacted with toluene diisocyanate to obtain urethane alkyd. The prepared urethane alkyd was characterized and its properties were determined and compared with those of the conventional (glycerol/jatropha oil) and commercial urethane alkyds. The castor oil/jatropha oil-based urethane alkyd had a lower molecular weight and viscosity, a slightly lower hardness and greatly longer drying time than the conventional and commercial urethane alkyds, but otherwise the film properties were broadly similar, including being very flexible, with an excellent adhesion and high impact resistance. In addition, they also exhibited excellent resistance to water and acid.     

Estimation of dilute solution viscosity parameters of rubber seed oil alkyds

Viscosity measurements were carried out in methyl ethyl ketone (MEK) and dimethyl formamide (DMF) for rubber seed oil alkyds having oil content of 20 (I), 30 (II), 35 (III), 40 (IV), 50 (V), and 60% (VI). Viscosity molecular weights, intrinsic viscosities, and viscosity parameters K and α, characteristic for both polymers and solvents, were determined. Generally, solubility properties were found to depend on molecular weight and polarity of the alkyds and solvent. Intrinsic viscosities of the alkyds were larger in DMF than in MEK, suggesting DMF to be a better solvent than MEK for rubber seed oil alkyds. Molecular weights determined for the alkyds range from 441 for sample III to 1323 for sample V. The viscosity molecular weights are in reasonable agreement with the values determined for samples II–V in MEK and samples I–IV in DMF. The values of Huggin's constant for these alkyds were also determined. Data reported also suggest that rubber seed oil alkyds tend to tolerate relatively basic solvent, such as DMF. Fractionation of the alkyds was considered to be in respect of molecular weight and polarity of the alkyds, and results show that low-molecular-weight species constitute greater proportion of the alkyds. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1987–1992, 1998     

Modified rubber seed oil based polyurethane foams

In this work, rubber seed oil (RSO) was extracted with cyclohexane at room temperature for 24 h. The yield of RSO was about 40 %. The RSO was purified by using sodium hydroxide to eliminate some free fatty acids. Then the RSO was modified by simultaneous epoxidation and hydroxylation. Hydroxylated RSO (HRSO) had the hydroxylation extents 120 and 230 mgKOH/g with 2 h and 4 h reaction times, respectively. The chemical structures of the oils were studied by FT-IR and ¹H-NMR, and they were characterized also in other ways. Polyurethane foam samples based on the HRSOs were successfully prepared, and their physico-mechanical and thermal properties were also studied, with varied NCO index and water content in the formulations. The PUF230 had better thermal stability and compressive strength but lower density than the PUF120. Both the NCO index and the water content had large effects on density, cell size, and compressive strength of the polyurethane foams.     

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。     

Molecular weight distribution in alkyd resins. Part II. Castor oil and hydrogenated castor oil alkyds

Alkyds prepared from castor and hydrogenated castor oils have been prepared direct from the oil and by first subjecting the oil to a glycerolysis reaction. The molecular weight distributions of the alkyds have been measured in solvent systems designed to separate predominantly on polarity and molecular weight. The properties of the alkyds in stoving enamels have been evaluated. The results are discussed in relation to existing theories relating processing conditions to molecular weight distribution in alkyd resins. Previous suggestions regarding the reactivity of the hydroxyl groups in the oil molecules are not consistent with the results obtained in this study.     

Synthesis and properties of acrylate functionalized alkyds via a Diels–Alder reaction

The α-eleosterate pendent fatty acid of a tung oil based alkyd was functionalized via a Diels–Alder reaction with three different acrylate groups: (1) 2,2,2-trifluoroethyl methacrylate, (2) 3-methacryloxypropyl trimethoxysilane, and (3) triallyl ether acrylate. The modified alkyds were characterized by using ¹H NMR, ¹³C NMR, and gel permeation chromatography (GPC). The drying time was measured at ambient temperature. The viscoelastic properties of the alkyd-modified films were measured using dynamic mechanical thermal analysis. The viscoelastic and drying time results show that the alkyd modified with siloxane and triallyl group affords a faster drying time, higher crosslink density, and higher glass transition temperature compared to the unmodified alkyd, whereas the fluorinated alkyd possesses surface active properties, but suffers in terms of drying and crosslinking density.     

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.     

水溶性醇酸树脂涂料的进展

综述了水溶性醇酸树脂的设计,合成,改性研究及应用,详细讨论了水溶性醇酸树脂涂料的干燥性能,指出了水溶性醇酸树脂的发展趋势。     

Analytical and physical investigation of alkyd resin in the course of its preparation. II. Study of condensation reaction and molecular weight distribution of alkyd

During preparation of alkyd resin by reaction between isocaprylic acid, phthalic anhydride, glycerol, and pentaerythritol the samples were successively taken away from the batch at different stages of the process and evaluated by analytical and physical ways. Acid numbers, hydroxyl numbers, and saponification numbers were determined by analyses of the samples and number-average molecular weights of alkyds were determined from vapor pressure osmotic measurements of their solutions. The extent of intramolecular esterification reactions (4–5%) was determined from these values. Molecular weight polydispersities in alkyd samples prepared at higher degrees of conversion were estimated by means of GPC measurements, and weight-average molecular weight of the final alkyd resin was calculated by using theoretical relationships derived for nonlinear condensation polymers.     

Nutritional and toxicological evaluation of rubber seed oil

Rubber (Hevea brasiliensis) seed oil (RSO) is available in India (Ca. 4500 tons per year) and is used mainly as a drying oil. The oil does not contain any unusual fatty acids, and it is a rich source of essential fatty acids C_18∶2 and C_18∶3 that make up 52% of its total fatty acid composition. Acute toxic potential in rats and the systemic effects and nutritional quality were assessed in a 13 week feeding study in weanling albino rats using a diet containing RSO or groundnut oil (GNO) (as the control) at a 10% level as the sole source of dietary fat. RSO did not manifest any acute toxic potential. Food consumption, growth rate and feed efficiency ratio of rats fed RSO were similar to those fed GNO. The digestibility of this oil was found to be 97%, as compared to 94% for GNO. There were no macroscopic or microscopic lesions in any of the organs which could be ascribed to the RSO incroporation in the diet. Thus the current data show that RSO could be used for edible purposes. However, it will be necessary to process the oil to achieve deodorization and to remove free fatty acids to make it organoleptically acceptable.     

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.     

Review of autoxidation and driers

This article is an overview of the chemistry and driers used in autoxidatively cured coatings and in particular alkyds. The drying process for alkyds and other unsaturated fatty acid materials is based on a series of chemical reactions known as autoxidation. The autoxidative process is usually catalyzed by metal salts known as driers. Numerous of investigations have elucidated the catalytic activity and reaction mechanism of the drying process. Spectroscopic techniques, especially mass spectrometry, have been used to study the autoxidation process and its products. Recent investigations on the oxidative drying of alkyd coating films are presented with a focus on both metal based and more environmental friendly means of catalysis.     

Oil-acrylic hybrid latexes as binders for waterborne coatings

The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying and gloss and color retention properties of acrylic latexes have mainly been directed towards the modification of the alkyd with an acrylate during alkyd synthesis followed by emulsification. This paper describes the preparation and application of oil-acrylic hybrid latexes as binders for waterborne coatings. The hybrid latexes were prepared using hydroperoxidized triglycerides as initiators for the mini-emulsion polymerization of acrylates in an Fe(II)/EDTA/SFS redox system. The particle morphology of hybrids initiated by fatty-acid hydroperoxides was compared with tert-butyl hydroperoxide-initiated systems. Cryo-TEM analysis indicated that, whereas tert-butyl hydroperoxide initiation resulted in the formation of heterogeneous particles, fatty-acid hydroperoxide-initiated hybrid particles showed no intra-particle heterogeneity. An AFM study of the film formation process of the oil/alkyd-acrylic hybrid latexes showed that phase separation occurred between the oil and the acrylic phases upon drying, resulting in films that consist of deformed acrylic particles embedded in a continuous matrix of oil. This results in a very smooth surface of the film.     

An investigation on synthesis of alkyd resin with sorbitol

Sorbitol, as an abundant, cheap and renewable resource, is considered as a potential raw material for the manufacture of alkyd resin. In this study, the kinetics on preparation of alkyd resin using phthalic anhydride, sorbitol and soya bean fatty acid as raw materials is investigated. Three kinds of sorbitol based alkyd resins (SAR) samples having fatty acid content (OL_f) of 42% (SAR1), 52% (SAR2) and 62% (SAR3) were prepared with phthalic anhydride, sorbitol aqueous solution and soya bean fatty acid using fatty acid method. Kinetic studies showed that the initial and latter stages of the reaction follow a second-order rate law. The second-order rate constants were found to be of the order of 10⁻⁵ g/mg KOH/min. Molecular weight and polydispersity index were determined by GPC and end-group analysis. The number average molecular weight of the alkyd resins ranged from 1435 to 1626 and the weight average molecular weight ranged from 3041 to 3648. A large polydispersity index was found in a range from 2.12 to 2.24. The varnish of alkyd resin SAR1 containing 50% 200# solvent gasoline and 1.25% cobalt naphthenate (drying agent) by weight dried faster than the others. The physical and chemical film properties of the sorbitol based alkyd resins were determined and compared with standard alkyd resins. The results showed that the performance of alkyd resin having fatty acid contents (OL_f) of 42% (SAR1) was almost the same as the standard alkyd resins. It could be a choice binder for alkyd resin paint and helpful to reduce production cost.     

Waterborne silicone-organic hybrid coatings for exterior applications

Waterborne alkyd and acrylic resins can be modified with silicone intermediates to improve their weather resistance in paints for exterior applications. The alkyds are modified through copolymerization before dispersion in water, using formulations and process conditions that minimize the tendency to gel. Acrylic latexes can be post treated with selected silicone intermediates at ambient temperature to give hybrid coating binders. In both cases, the gloss retention and chalking resistance of paint films are greatly increased.