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.     

Solvent-blown,rigid urethane foams from low cost castor oil-polyol mixtures

The preparation of solvent-blown rigid urethane foams from low cost castor oil-polyol mixtures was investigated. Solutions of triisopropanolamine, and of mixtures of triisopropanolamine and triethanolamine in castor oil, were used as the polyol component of these foams. Foams were prepared by reacting these polyol mixtures, in the presence of catalyst, surfactant, and trichlorofluoromethane, with prepolymers prepared from toluenediisocyanate and certain polyether polyols or mixtures of these polyether polyols with castor oil. The effect of polyol and prepolymer composition and blowing agent concentration on such foam properties as density and compressive strength was investigated. The properties of the castor oil-based foams were comparable to those of foams obtained from more costly polyols. Presented at the Spring Meeting of the American Oil Chemists' Society, St. Louis, Missouri, May 1–3, 1961. A laboratory of the Western Utilization Researchand Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

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.     

Rigid urethane foams from hydroxymethylated linseed oil and polyol esters

Rigid urethane foams were prepared from hydroxymethylated linseed oil and its esters of glycerol, trimethylolpropane and pentaerythritol. These polyols were made by selective hydroformylation with a rhodium-triphenylphosphine catalyst followed by catalytic hydrogenation with Raney nickel. Although the hydroxymethylated linseed monoglyceride by itself yielded a satisfactory foam, better foams were made from all hydroxymethylated linseed derivatives when blended with a low-molecular weight commercial polyol. Linseed-derived foams were compared with foams from equivalent formulations of hydroxymethylated monoolein and castor oil. Hydroxymethylated products yielded polyurethane foams meeting the requirements of commercial products with respect to density, compressive strength and dimensional stability. National Flaxseed Processors Association Fellow. N. Market. Nutr. Res. Div., ARS, USDA.     

Rigid polyurethane foams from diethanolamides of carboxylated oils and fatty acids

New polyols of high hydroxyl content and reactivity were made from linseed and soybean oils and acids by catalytic carboxylation followed by reaction with diethanolamine. Urethane foams made with these diethanolamides were stronger than those made with castor oil at equivalent polyol wt. Because of their higher hydroxyl content, a larger amount of diethanolamides could be incorporated in foam formulations than is possible with castor oil. The rigid urethane foams prepared with the new polyols meet the requirements of commercial products with respect to density, compressive strength, and dimensional stability. National Flaxseed Processors Association Fellow, 1969–1973. Present address: Avery Products, Technical Center, 325 North Altadena Dr., Pasadena, CA 91107.     

Polyisobutylene-based urethane foams

Summary The rates of urethane formation between linear and three-arm star hydroxyl-terminated polyisobutylenes (PIB-diols and -triols) and 4,4-diphenylmethane diisocyanate (MDI) have been studied in the presence of triethylene diamine and stannous octoate catalysts in chlorebenzene at 25°C. The second order rate constants were determined and compared with those obtained with various polyether triols, hydroxyl-terminated polybutadiene and hydroxyl-terminated polyolefin. The rates of the normalized PIB-diol/MDI and PIB-triol/MDI reactions are essentially identical. In the presence of triethylene diamine, the rates of the PIB-diol and PIB-triol/MDI reactions are the same or much higher than that of the polyether-triol/MDI reaction. In contrast, in the presence of stannous octoate, the rates of the PIB-diol and PIB-triol/MDI reactions are much slower than that of the polyether-triol/MDI reaction. Differences in catalytic pathways are invoked to explain these observations. The reactivities of hydroxyl-terminated PIBs are similar to those of other hydroxyl-terminated polyhydrocarbons and sufficient for the synthesis of foams.     

Solvent-blown rigid urethane foams from castor-based polyols

The preparation of trichlorofluoromethane-blown rigid urethane foams using toluenediisocyanate and castor oil-derived polyols was investigated. The castor-based polyols included castor oil, hydroxylated castor oil, technical glycerol-, penta-erythritol-, and sorbitol monoricinoleates, and N,N-bis(2-hydroxyethyl) ricinoleamide. The last of these yielded the best foams when used as the sole polyol component added to the prepolymer. However better foams were obtained by using, as the polyol component, a mixture of a castor oil-derived polyol and a lower-molecular-weight polyol with a higher hydroxyl content. These polyol mixtures yielded more highly cross-linked polymers and hence foams with higher compressive strengths and less tendency to shrink after foaming. The effect of catalyst, silicone surfactant, and trichlorofluoromethane content was also investigated. An empirical relationship between density and compressive strength in a given foam system was derived. Presented at the fall meeting, American Oil Chemists' Society, New York, October 17–19, 1960. A laboratory of the Western Utilization Research and Development Division. Agricultural Research Service, U.S. Department of Agriculture.     

New castor oil-based urethane elastomers

Urethane elastomers with a wide range of properties were prepared by reaction of toluene diisocyanate, diphenylmethane diisocyanate or an aliphatic diisocyanate with a series of castor oil derivatives. The castor derivatives included amides prepared by reaction of castor oil with mono- or dialkanolamines, amides of ricinoleic acid with long chain di- and triamines, butanediol diricinoleate and the commercial products-castor oil itself and the monoricinoleates of propylene glycol and pentaerythritol. Elastomers were also prepared from commercial polyether diols for comparison. Properties evaluated include hardness, resilience, tear strength, stress-strain properties, compression set and resistance to water and oil. Particularly high tensile and tear strengths were obtained from the amides. Softer products with good properties were obtained from propylene glycol monoricinoleate and from mixtures of the amides with castor oil or butanediol diricinoleate. Improved products were obtained by the use of diphenylmethane diisocyanate in place of toluene diisocyanate. Presented at the AOCS Meeting, Los Angeles, April 1972. ARS, USDA.     

Castor polyols for urethane foams

Summary A systematic investigation of some 21 castor polyols as base materials for preparing urethane foams was carried out. Prepolymers were prepared both from individual castor polyols and from mixtures of them with an anhydrous castor oil. Foams formed from these prepolymers were checked for shrinkage on cure, density, and modulus. From the wide range of results obtained it is evident that castor polyols can serve as effective urethane components. Aside from serving as major polyols for reaction with di-isocyanates, they can also be used as modifying polyols a) to speed up prepolymer preparation, b) to adjust prepolymer viscosity to any required degree, c) to minimize loss of modulus on humid aging, and as cross-linking centers with negligible loss of foam modulus. Details covering the preparation of a nonshrinking, semi-rigid, light-weight urethane foam based on an 85% anhydrous castor oil/15% epoxidized castor oil mix are outlined in the article. Presented at the Spring Meeting, American Oil Chemists' Society, Memphis, Tenn., April 20–23, 1958.     

Water blown free rise polyurethane foams

A model is developed in this work for predicting the bubble size distribution in polyurethane foams generated by using water as a chemical blowing agent. The model combines equations of energy balance, kinetics of the reactions of isocyanate with water and polyol, and nucleation and growth of CO₂ bubbles. It is found that as the water content of the reaction mixture is increased, the mean bubble size decreases and the bubble size distribution become narrower. Exactly the opposite occurs in polyurethanes foamed with a physical blowing agent, e.g., DuPont Freons. This suggests that a combination of physical and chemical blowing agents can be employed to control bubble size distribution.     

Carbon foams prepared from polyimide using urethane foam template

Polyimide and carbon foams were successfully prepared using polyurethane foams as a template. Impregnation of polyimide precursor, poly(amide acid), followed by imidization at 200 °C gave polyurethane/polyimide (PU/PI) composite foams, which resulted in PI foams by heating above 400 °C and then carbon foams above 800 °C. Foams carbonized at 1000 °C were graphitized by the heat treatment at 3000 °C, keeping foam characteristics. Two applications of these carbon foams, i.e., an adsorbent of ambient water vapor and a substrate of photocatalyst anatase TiO₂, were experimentally confirmed. For the former application, the present foam could be characterized by prompt adsorption of ambient water vapor. Some of carbon foams prepared were floating on water, even after loading photocatalyst anatase, which might be advantageous for photodecomposition of pollutants in water in respect to the UV rays efficiency.     

Urethane foams from animal fats. IV. Rigid foams from epoxidized glycerides

Liquid polyols have been prepared from epoxidized glyceryl trioleate, glyceryl monooleate, lard oil, neatsfoot oil, and soybean oil by hydration with 24% fluoboric acid. Upon adjustment of the equivalent weight to 100 with triisopropanolamine, the polyols were foamed by reaction with a prepolymer made from oxypropylated sorbitol and tolylene diisocyanate. The resulting rigid foams had densities between 1.66 and 2.34 lbs/ft³ and compressive strengths ranging from 23 to 39 psi (10% compression). The same polyols were used in one-step systems with PAPI as the isocyanate. In general, foam properties were comparable with those obtained from the prepolymer systems. Presented at the AOCS Meeting, New Orleans, 1967. E. Utiliz. Res. Dev. Div., ARS, USDA.     

Rigid polyurethane foams from a soybean oil-based Polyol

Polyurethane (PU) rigid foams were synthesized by substituting a polypropylene-based polyol with soybean oil-based polyol (SBOP). All the soy-based foams maintained a regular cell structure and had even smaller average cell size than the control foams. The density of soy-based foams was within 5% of the controls, except that the density of foams from 100% SBOP was 17% higher. Soy-based foams also had comparable initial thermal conductivity (k value) and closed cell content, higher T_g and compressive strength. However, while foams from 50% SBOP showed similar increase in k value to the 0% SBOP foams, under accelerated aging conditions, the 100% SBOP foams aged faster. Gas permeation tests performed on PU thin films showed higher N₂ permeation for PU thin films made from SBOP which is believed to be the cause of accelerated thermal aging.     

Synthesis of triglyceride estolides from lesquerella and castor oils

Triglyceride (TG) estolides were synthesized from the hydroxy moieties of lesquerella and castor oils with oleic acid. Complete esterification of the hydroxy oils was possible when a slight excess of oleic acid was employed (1 to 1.5 mole equivalents). The estolides could be formed in the absence of catalyst at 175 to 250°C under vacuum or a nitrogen atmosphere. The optimal reaction conditions were found to be under vacuum at 200°C for 12 h for lesquerella and 24 h for castor oil. The lesquerella esterification reaction was completed in half the time of the for castor and with lower equivalents of oleic acid due to the difunctional hydroxy nature of lesquerella TG compared to the trifunctional nature of castor TG. Interesterification or dehydration of the resulting estolides to conjugated FA was not a significant side reaction, with only a slight amount of dehydration occurring at the highest temperature studied, 250°C. Use of a mineral-or Lewis-acid catalyst increased the rate of TG-estolide formation at 75°C but resulted in the formation of a dark oil, and the reaction did not go to completion in 24 h. Estolide numbers (i.e., degree of estolide formation) for the reaction and characterization of the products were made by ¹H NMR and ¹³C NMR. The decrease in the hydroxy methine signal at 3.55 ppm was used to quantify the degree of esterification by comparing this integral to the integral of the alpha methylene protons on the glycerine at 4.28 and 4.13 ppm.     

Rigid polyurethane foams derived from cork liquefied at atmospheric pressure

The aim of this study was to evaluate the possibility of using polyols derived from liquefied cork in the production of novel bio‐based polyurethane foams (PUFs). For that purpose, different liquefaction conditions were used at atmospheric pressure and moderate temperature where poly(ethylene glycol) and glycerol were used as solvents and sulfuric acid as catalyst. The ensuing polyols were used to produce foams which were characterized using structural, morphological, thermal and mechanical analyses to demonstrate that liquefaction conditions play a crucial role in the properties of the foams. The resulting foams exhibited the typical cellular structure of PUFs with low densities (57.4–70.7 kg m^?3) and low thermal conductivities (0.038–0.040 W m^?1 K^?1). However, the mechanical properties differed significantly depending on the liquefaction conditions. The best stress–strain results were obtained for PUFs prepared using the polyol with lowest I_OH and water content (Young's modulus of 475.0 kPa, compressive stress (σ_10%) of 34.6 kPa and toughness of 7397.1 J m^?3). This PUF was thermally stable up to 200 °C and presented a glass transition temperature of around 27 °C. The results obtained demonstrate that these polyols from liquefied cork yield PUFs that are adequate materials for insulation applications. © 2014 Society of Chemical Industry     

Synthesis and characterization of castor oil urethane triamine networks

Castor oil was polymerized with diisocyanate and crosslinked with primary triamine (Jeffamine T-403) to form networks. The effect of triamine as a crosslinking agent on rubbery castor oil urethane elastomer was determined by measuring network parameters such as average molecular weight between crosslinks (MC) number of polymer chains per unit volume (N), tensile strength, and modulus of the networks. The crosslinking density was varied by varying the ratio of NCO : NH₂ from 0.60 to 0.95. The results indicated the formation of highly crosslinked elastomers at all NCO : NH₂ ratios employed. The tensile stregth and modulus increased with increasing crosslink density up to a value of NCO : NH₂ 0.85 and after this there was no significant change, indicating the maximum limit of improvement attainble in terms of network characteristics.     

Preparation and characterization of water‐blown polyurethane foams from liquefied cornstalk polyol

Polyurethane foams were prepared from the liquefied cornstalk polyol, which was obtained by the liquefaction of cornstalk in the presence of polyhydric alcohols using sulfuric acid as catalyst. The advisable liquefaction reaction conditions were selected by investigating their influences on the properties of liquefied cornstalk polyol, taking account of the requirement for the preparation of appropriate polyurethane foams. The influences of the contents of catalysts, water, surfactant, and isocyanate on the properties of polyurethane foams were also discussed, and feasible formulations for preparing cornstalk‐based polyurethane foams were proposed. The results indicated that the foams prepared from such liquefied cornstalk polyol exhibited excellent mechanical properties and thermal properties, and could be used as heat‐insulating materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Desaminated glycolysis of water‐blown rigid polyurethane foams

Glycolysis reaction kinetics of methylene diphenyl diisocyanate‐based water‐blown polyurethane foams was examined by gel permeation chromatography. Glycolysates were reacted with butyl glycidyl ether to convert toxic aromatic amines to polyols, and their products were identified by ¹H‐NMR spectroscopy. To examine the quality of recycled polyol, polyurethane foams were reprepared using the virgin and recycled polyol mixtures with varying compositions. Cell structures and sizes of reprepared foams were similar to those of original ones when the recycled polyols were mixed up to 30 wt %. Density, thermal conductivity, and flexural strength of the reprepared foams were compared with those of the original ones, and no difference was observed below the recycled polyol concentration of 30 wt %. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2646–2656, 2000