Elastomers from castor oil

Castor oil has been used to prepare millable elastomers by using 2,4-toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, and 1,5-naphthalene diisocyanate, respectively. These elastomers are vulcanized with sulfur and 4,4′-diphenylmethane diisocyanate separately by using the standard methods of rubber technology, and the properties of these vulcanizates are reported.     

Ceramer coatings from castor oil or epoxidized castor oil and tetraethoxysilane

New inorganic-organic hybrids were synthesized through the reaction of castor oil (CO) or epoxidized castor oil (ECO) with tetraethoxysilane (TEOS). The mass proportions of ECO/TEOS varied from 90∶10 to 60∶40, and films of the material were thermally cured. An IR spectroscopy analysis was performed, and macro- and microscopic properties such as adhesion, hardness, swelling in toluene, microstructure (scanning electron microscopy), and T _g were investigated as a function of the proportion of their inorganic-organic precursor. Morphologic studies showed that the hybrid films were homogeneous when lower proportions of the inorganic precursors were used. Hardness and tensile strength increased with TEOS concentration, whereas swelling in toluene decreased with TEOS concentration. Good adhesion was observed throughout the hybrid series.     

Microwave-assisted solvent extraction of castor oil from castor seeds

This study was aimed at evaluating the physicochemical properties and oxidation stability of castor oil using microwave-assisted solvent extraction (MAE). MAE was performed using 5% ethanol in hexane as solvent at different extraction times, power intensities and solvent-to-feed (S/F, ml of solvent to gram of feed) ratios. The process parameters were optimized by statistical approach using historical data design of response surface method (RSM). The oils were characterized for yield, physicochemical properties, dielectric properties and oxidation stability, and comparison was also made with oil extracted using Soxhlet method. Results show that the maximum oil yield of 37% was obtained at 20 min with microwave power intensity of 330 W and S/F ratio of 20. The main fatty acid composition of castor oil is ricinoleic acid. The density, refractive index, dielectric properties and oxidation stability of oils are not affected by the extraction methods and extraction parameters of MAE. However, the MAE-extracted oil is more viscous compared to that by Soxhlet method. With extra caution on oil oxidation, MAE could be a promising solvent extraction method with an 86% less in processing time and a higher yield.     

The preparation and properties of some urethane foams from castor oil and elaidinized castor oil

Summary The preparation and properties of two series of castor oil urethane foams, one from castor oil and the other from elaidinized castor oil, were investigated. The first series of foams was made from prepolymers containing 60% of castor oil prepared at increasing temperature levels to vary the degree of crosslinking in the final foams. These foams had lower tensile strengths than observed for a previously prepared foam of 60% castor oil and did not show significant differences in water resistance as crosslinking varied. They were increased nearly 100% in compressive strength with increased crosslinking and had very good shrinkage characteristics as values of only 1 to 2% were obtained. A second series of foams was prepared from 50, 60, 70, and 80% of elaidinized castor oil to compare with foams from a similar series from castor oil. This series of foams of 50 to 80% elaidinized castor oil contents was similar in density (1.7 to 6.7 lbs./cu. ft.), had improved shrinkage characteristics (11, 1, 3, and 4%, respectively), showed increased compressive and tensile strengths (up to 12.1 p.s.i. at 50% compression modulus and 34.7 p.s.i. ultimate tensile for the 60% foam formulation), and had better water-resistance properties (411 to 155%vs. 515 to 170% water absorption) than the analogous foams from castor oil. In general, humid aging only slightly affected the values obtained for the foams and was significant in only a few instances,e.g., decreased tensile in the elaidinized castor oil series. Thus increasing crosslinks in the foam apparently did not improve water resistance but did improve shrinkage characteristics in addition to some increased strength properties, as would be anticipated. Foams from elaidinized castor oil, while similar in density and foaming characteristics to analogous foams from castor oil, exhibited less shrinkage and improved water-resistance. Presented at the 50th Annual Meeting of the American Oil Chemists' Society, New Orleans, La., April 20–22, 1959. Ono of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Heptaldehyde and undecylenic acid from castor oil

Castor Oil was pyrolyzed in a vertical stainless steel tubular reactor packed with 12.5-mm diameter mild steel balls in presence of 0.5% benzoyl peroxide. The operating parameters were optimized to obtain high yields of heptaldehyde and undecylenic acid. Heating at 550 C under reduced pressure of 45 mm (Hg) yielded 24.8% heptaldehyde and 36.0% undecylenic acid.     

Cationic ultraviolet curable coatings from castor oil

Coatings formulated from castor oil glycidyl ether (COGE), epoxy resin UVR 6100, and photoinitiator UVI 6990 produced smooth coatings with excellent gloss and good flexibility, adhesion, gloss retention, and water resistance. Formulations containing up to 50% COGE afforded promising coating performance attributes. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 8–13, 2000     

Studies on castor oil. II. Hydrogenation of castor oil

1. Products of low iodine value (<10.0) and hydroxyl value (35–40) can be readily obtained by hydrogenating castor oil at atmospheric pressure and at temperatures of the order of 220°, using 1.0% Raney nickel.
2. Dehydration of ricinoleic acid and subsequent hydrogenation of the resulting double bond as also simple saturation of ricinoleic acid are the main reactions occurring during the hydrogenation of castor oil under ordinary conditions.
3. Increase in the amount of catalyst favors more the hydrogenation of double bond at lower temperatures and both dehydration and hydrogenation at about 220°, which seems to be the optimum temperature for the maximum conversion of ricinoleic acid into nonhydroxy acids with both Raney and dryreduced nickel at atmospheric pressures.
4. Higher proportions of catalyst, addition of catalyst stepwise, and higher temperature of hydrogenation cause considerable splitting and estolide formation.
5. When hydrogenation is carried out at room temperature, under a pressure of 40 p.s.i. with alcohol as solvent, a product rich in monohydroxy stearic acid is obtained.
6. True unsaturation of hydrogenated castor oil is measured by the Wijs method at 15–20°C.

     

Synthesis of methyl 9,12-epoxyoctadecanoate from castor oil

We report here the synthesis of methyl 9,12-epoxyoctadecanoate (2-[7-methoxycarbonyl-heptyl]-5-hexanyl-tetrahydrofuran). Methyl ricinoleate (methyl 12-hydroxy-9-cis-octadecenoate), isolated from castor oil methyl esters was isomerized with diphenyl disulfide as radical initiator under ultraviolet radiation to give thetrans isomer, methyl ricinelaidate. The latter was cyclized by slow addition of 10% bromine solution in dichloromethane to give methyl 10-bromo-9,12-epoxyoctadecanoate, which on hydrogenation with Pd/C catalyst gave the title compound, methyl 9,12-epoxyoctadecanoate.     

The preparation of stearic acid from castor oil

Summary By de-hydroxylating the 12-hydroxystearic acid, which may be prepared in a pure state by the alcoholysis of fully hydrogenated castor oil, there may be obtained in at least 40% yield an exceptionally pure stearic acid whose solidification point is the same as that of a similar product previously reported by others (1). Avoided by the procedure described are recourse to the necessity of preparing lead soaps for the removal of unsaturated fatty acids and the drudgery of repeated crystallizations as prescribed by other published methods. From the doctoral dissertation of D. A. Roth. University of Wisconsin, May, 1944.     

Isocyanate-modified dehydrated castor oil

Esters of dehydrated castor oil fatty acids with polyhydric alcohols like ethylene glycol, propylene glycol, glycerol, pentaerythritol and sorbitol have been prepared. The esters, having hydroxyl value ranging from 78.5 to 167, were reacted with toluene diisocyanate. The scratch hardness and other film properties of the resulting urethanes have been studied. Urethanes obtained from various mixtures of the above esters also have been studied. The best results have been obtained when a mixture of ethylene glycol ester and plenaerythritol ester of dehydrated castor oil fatty acids in the ratio of 4:1 are reacted with one equivalent of toluene diisocyanate. One equivalent of glycerol ester (hydroxyl value 78.5), ethylene glycol ester (hydroxyl value 167), or propylene glycol ester (hydroxyl value 159.4) of DCO fatty acids when reacted with 1.25 equivalent of toluene diisocyanate also gave satisfactory products.     

Sebacic acid and 2-octanol from castor oil

Alkali pyrolysis of castor oil was carried out in the presence of white mineral oil. The operating parameters were optimized to obtain high yields of 2-octanol and sebacic acid. Alkali pyrolysis at 280±2°C in the presence of 1% red lead catalyst yielded 70.1% 2-octanol and 72.5% sebacic acid on the basis of their respective theoretical yields. Paper presented in ISF-JOCS World Congress 1988, held at Tokyo, Japan.     

Rigid urethane foams from hydroxymethylated castor oil,safflower oil,oleic safflower oil,and polyol esters of castor acids

Castor, safflower, and oleic safflower oil derivatives with enhanced reactivity and hydroxyl group content were prepared by hydroformylation with a rhodium-triphenylphosphine catalyst, followed by hydrogenation. Rigid urethane foams prepared from these hydroxymethylated derivatives had excellent compressive strengths, closed cell contents, and dimensional stability. Best properties were obtained from hydroxymethylated polyol esters of castor acids.     

Some physical properties of castor oil esters and hydrogenated castor oil esters

Esters of castor oil and hydrogenated castor oil were prepared with C₆, C₁₂, C₁₆, C₁₈ fatty acids, using tetra‐n‐butyl titanate as a catalyst and n‐butyl benzene as a water entrainer. Physical properties such as melting point, refractive index, viscosity, and specific gravity of these esters were measured. Slip melting points of the esters were very low in both cases. These esters did not crystallize even at low temperature. The highest slip melting point obtained was 21 °C with stearoyl hydrogenated castor oil ester and lowest slip melting point obtained was —6 °C with hexanoyl castor oil ester.     

Novel dielectrics from IPNs derived from castor oil based polyurethanes

Three series of interpenetrating polymer networks (IPNs) based on a polyurethane (castor oil + toluene diisocyanate) with polystyrene, poly(methyl methacrylate), and poly(n-butyl methacrylate) were synthesized and characterized. Dielectric relaxation studies of these IPNs were carried out from ?150 to 100°C in the 100 Hz to 100 kHz range. The effects of structural variables such as composition, type of vinyl monomer, as well as the effect of interaction of the phases on the dielectric properties were studied. A certain degree of phase mixing was observed to exist in all series as detected by the variation of the glass-transition temperatures of the IPNs. Maxwell–Wagner–Sillars polarization at the interface of the two phases was observed. © 1994 John Wiley & Sons, Inc.     

Studies on castor oil. I. Fatty acid composition of castor oil

Summary Methyl esters of castor oil were prepared by saponifying the oil with potassium hydroxide in methanol, splitting the potassium soapsin situ with an excess of hydrochloric acid, and esterifying at room temperature. The esters had hydroxyl values comparable with those of the parent oils. The methyl esters were quantitatively resolved into hydroxy and nonhydroxy esters after reacting with succinic anhydride in toluene. The composition of castor oil was calculated from a) amount of nonhydroxy esters, b) methyl linoleate content of methyl esters determined spectro-photometrically, c) iodine value of the methyl esters determined by the Wijs method at 15–20°C., and d) iodine value of the nonhydroxy esters determined by the Woburn method. This composition was confirmed by the estimation of saturated acids in one sample and dihydroxystearic acid in all. Castor oil was readly hydrogenated with Raney nickel in alcohol at room temperature (30–33°C.) without any hydrogenolysis of the hydroxyl groups. Methyl dihydroxystearate content of the methyl esters of this hydrogenated oil was determined by reaction with 80–100% excess periodic acid at 15–20°C. Part of a thesis submitted for the Ph.D. degree to the University of Bombay.     

The role of castor oil in epoxy and polyamide systems for coating and adhesive application

Summary  Over the past few years, the challenges of globalisation, consolidation and economical point of view have meant that manufacturers of epoxy formulations have to constantly improve their capability to meet the needs of customers. An active area for advancement is that of epoxy and polyamide resin with castor oil. Generally, people working in the coating industries are familiar with castor oil, but this paper provides information on the new use of castor oil in epoxy and polyamide resin. This novel product (castor oil-modified epoxy resin/castor oil-modified polyamide) provides a previously unattainable combination and improved flexibility and toughness to a variety of ambient cure applications. This communication will review the performance of these castor oil-modified epoxy and polyamide resin surface coatings and adhesives. Based on the results of this study, these systems offer some advantages without much affecting the traditional properties of epoxy and polyamide resin in a variety of applications.     

Interpenetrating polymer networks from castor oil and dibasic acids

Prepolyesters were obtained from castor oil and dibasic acids, viz oxalic, malonic, succinic, glutaric, adipic, suberic and sebacic acid. These prepolyesters (PPE) were subsequently interpenetrated with methyl methacrylate containing 1% ethylene glycol dimethacrylate as crosslinker by radical polymerization initiated with benzoyl peroxide. The novel PPE poly(methyl methacrylate) PPE/PMMA interpenetrating polymer networks (IPNs) were obtained as powder. They were characterized by solubility behaviour, IR spectral study and thermal behaviour.