Rubber-toughening epoxy thermosets with epoxidized crambe oil

Epoxidized crambe oil and rapeseed oil were synthesized by reaction of the oils with m-chloroperoxybenzoic acid. Formulating the neat epoxidized oils with epoxy-amine systems gave two-phase thermosets with epoxidized crambe oil, but not with epoxidized rapeseed oil. Glass transition temperature, mechanical properties, and fracture toughness of the epoxidized crambe oil thermoset specimen were measured. Fracture toughness values of the epoxy thermosets were increased approximately 100% by both 5 and 10% epoxidized crambe oil. Glass transition temperature and mechanical properties were affected only modestly.     

Alkali-catalyzed alcoholysis of crambe oil and camelina oil for the preparation of long-chain esters

The alcoholysis of crambe and camelina oils was carried out with oleyl alcohol, alcohols derived from crambe and camelina oils, and n-octanol using potassium hydroxide as catalyst to prepare alkyl esters. Conversions to alkyl esters were about 0% with oleyl alcohol, 20–45% with crambe and camelina alcohols, and 60% with n-octanol. The conversion to esters for crambe and camelina oil with oleyl alcohol and n-octanol increased with increasing molar excess of alcohol. Composition of the alkyl esters formed was as expected from the composition of the reaction partners. Presented as part of the doctoral thesis of Georg Steinke to the University of Münster, Münster, Germany.     

Lipase-catalyzed alcoholysis of crambe oil and camelina oil for the preparation of long-chain esters

Crambe oil and camelina oil were transesterified with oleyl alcohol, the alcohols derived from crambe and camelina oils, n-octanol or isopropanol using Novozym 435 (immobilized lipase B from Candida antarctica), Lipozyme IM (immobilized lipase from Rhizomucor miehei), and papaya (Carica papaya) latex lipase as biocatalysts. The highest conversions to alkyl esters were obtained with Novozym 435 (up to 95%) in most cases, whereas Lipozyme IM and papaya latex lipase gave lower (40 to 50%) conversions. The conversions with long-chain alcohols (oleyl alcohol, crambe alcohols, and camelina alcohols) were higher (40 to 95%) than with medium-chain n-octanol (30 to 85%). Isopropyl esters of crambe oil and camelina oil were obtained with rather low conversions using Novozym 435 (<40%) and Lipozyme IM (about 10%) as biocatalysts, whereas with papaya latex lipase no isopropyl esters were formed. The conversions of crambe oil and camelina oil to oleyl and n-octyl esters using Novozym 435 as biocatalyst were hardly affected by the ratio of the substrates, but with Lipozyme IM the conversions to alkyl esters distinctly increased with an excess of alcohol substrate Presented as part of the doctoral thesis of Georg Steinke to the University of Münster, Münster, Germany     

Secondary products from high pressure hydrogenation of crambe oil

Hydrogenation of crambe oil, mainly an α,α’-dierucoyl triglyceride, in the presence of cadmium promoted copper-chromite provides long chain waxes being sought as sperm whale oil replacements. Gas liquid chromatography and gas chromatography-mass spectrometry analyses of secondary products indicate, however, that reduction proceeds rather differently from Adkins-type hydrogenations of triglycerides over copper-chromium oxide catalysts. Monoand diunsaturated alkenes ranging from C₁₆-C₂₄, odd chain lengths included, constitute ca. 1% of the product. Esters of crambe acids with methyl, ethyl, n-propyl, and isopropyl alcohols account for less than 5%. These alcohols and traces of 1,2-propanediol from the hydrogenolysis of glycerol occur in either the head gas or the reaction mixture or both. In contrast to published results for Adkins-type hydrogenations of triglycerides, n-propyl alcohol is far more abundant than isopropyl alcohol or 1,2-propanediol. Isopropyl esters of C-18 acids are not present, and those of C-22 acids constitute no more than 2% of the total esters. Low proportion of isopropyl esters and enrichment of C-22 acids in the secondary products compared with C-18 acids suggest that the acyl substituent at the β-position of glycerol is eliminated during hydrogenation of crambe oil with a Cd−Cu−Cr catalyst. Presented at the AOCS Meeting, Mexico City, April 1974. ARS, USDA.     

Polymerization of allyl esters derived from long-chain fatty acids and palm olein

Allyl esters of palm olein, palmitic, and oleic acids were synthesized by transesterification and esterification methods using KOH and absolute H₂SO₄ as catalysts, respectively. Three allyl esters, namely, allyl palmitate, allyl epoxystearate, and epoxidized allyl ester of palm olein, were successfully polymerized in the presence of t-butyl perbenzoate at 120°C to obtain oligomers with the average number of backbone atoms approximately equal to the number of skeletal atoms of the long-dangling side chains. The kinetic data of polymerization were conformed to the rate equation proposed by other workers. No oxirane cleavage was detected during the chain reaction. The melting behavior of these comb-shaped polymers was compared with that of their respective allylic monomers. The polymer of epoxidized allyl ester of palm olein exhibits a glass transition temperature at 204.4 K. The critical molecular weights of the polymers of allyl esters investigated are predicted to be not lower than 10⁴.     

Dehulling crambe seed for improved oil extraction and meal quality

Crambe seed had low bulk density (328 kg/m³) due to thick hulls (0.23 mm), which made up 21.2% of the seed weight. The mean seed diameter was 2.7 mm (SD±0.2 mm); the thousand-grain-weight was 6.2 g. Dehulling improves oil extraction efficiency and facilitates the marketing of high-protein meal (>40% protein). The effectiveness of roller milling/aspirating and the effectiveness of impact milling/aspirating on dehulling crambe seed were studied and compared by analyzing the meat and hull fractions for oil and protein contents and calculating material balances. Roller milling was more effective than impact milling. The optimal roller mill gap was 7/64 in. (0.28 cm), and the optimal impact mill speed was 2,400 rpm generating 44.7 m/s tangential speed. The optimal aspiration airflow was 1,970 ft³/min (55.7 m³/min). Roller milling/aspirating was projected to produce 46% protein meal at 12% moisture and 1% residual oil (typical of solvent extraction) or 42% protein meal at 12% moisture and 6% residual oil (typical of screw pressing most other oilseeds). Hand-dissected hulls contained 10.4% moisture, and 1.2% oil and 8.8% protein on a dry basis, whereas the meats contained 8.8% moisture, and 47.6% oil and 31.6% protein on a dry basis. Optimal roller milling/aspirating produced hulls with 8.1% oil and 11.4% protein and meats with 42.6% oil and 30.5% protein on a dry basis.     

Processing of crambe for oil and isolation of erucic acid

Crambe seed (Crambe abyssinica) is an excellent, recently established source of high-erucic acid oil. Erucic acid has a number of important and potential applications. To develop this potential, a rapid bench-scale method was desired whereby purified erucic acid in up to several 100-g quantities could be produced from crambe seed. Using the method developed, oil was expressed from dried, intact seed; clarified, degummed, and bleached; and saponified and acidified to obtain the free fatty acids. Analysis by inductively coupled plasma of the free fatty acids showed negligible levels of phosphorus and most minerals. Erucic acid was twice crystallized from 95% ethanol at −14°C, resulting in a purity of 87.1%. This process yielded 365 g erucic acid crystals per kg bleached oil. Nuclear magnetic resonance analysis showed that the prepared erucic acid had an excellent pattern of correlation with a commercial standard. The time needed to convert 1 kg of crambe seed to erucic acid is about 48 h. Crystal filtration and drying stages under the current process conditions require 30% of the overall time. The method is suitable for producing adequate quantities of erucic acid for use in studies of its bench-scale conversion. There is obviously, still, a fruitful field of work to be explored in the formalization of refining procedures for crambe oil. It seems that crambe is destined to continue expansion into the high-erucic acid oil markets.     

Biobased epoxy resin from canola oil

Epoxidized canola oil (ECO)‐based thermoset epoxy resins were formulated with phthalic anhydride (PA) as the curing agent for different ratios of ECO to PA (1:1, 1:1.5, and 1:2 mol/mol) at curing temperatures of 155, 170, 185, and 200°C. The gelation process of the epoxy resins and the viscoelastic properties of the systems during curing were studied by rheometry, whereas the dynamic mechanical and thermal properties of the cured resins were studied by dynamic mechanical analysis (DMA) and differential scanning calorimetry. We found that the thermomechanical properties of the resins were not strongly dependent on the curing temperature of the resin, although elevated temperatures significantly accelerated the curing process. However, an increase in the curing agent (PA) amount significantly altered both the reaction rate and the thermomechanical properties of the final resin. Thus, in the ECO/PA system, the selection of the combination of the curing temperature and the molar ratios of the curing agent could be used to design thermoset resins with unique thermomechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40142.     

Allyl esters of crambe-derived long-chain fatty acids and their polymers

Allyl esters of erucic, brassidic, behenic, oleo-erucic, and stearo-behenic acids, prepared by refluxing benzene solutions of the acids with excess allyl alcohol in the presence of p-toluenesulfonic acid monohydrate, polymerize smoothly in the presence of 5 wt. % t-butyl perbenzoate at 120°C for 24 hr. Polymerization of the unsaturated acid esters involves a large portion (ca. 84%) of allylic and a small portion (ca. 26%) of ethylenic bonds. The products, saturated and unsaturated, have a degree of polymerization between 6 and 10 and are soluble in typical polymer solvents. Crystallinity, judged by thermal analysis, decreased with increased cis unsaturation. The oligomers melted between ?30°C and 59°C and started decomposing at 200°C.     

Rearrangement of epoxy fatty esters to keto fatty esters

The rearrangement of fatty epoxyesters to ketoesters was studied. The isomerization is carried out in nonaqueous media and is catalyzed by acids. Esters containing one epoxy group per fatty acid chain are isomerized to the corresponding ketones in 70–90% yields using boron fluoride etherate catalyst in boiling dioxane. Conversion to ketonic products is measured either by chromatographic separation followed by IR analysis or by oximation. Principal byproducts are hydroxy derivatives. Fatty esters containing more than one epoxy group/fatty acid chain give low ketone yields. A laboratory of the E. Utiliz. Res. & Dev. Div., ARS, USDA.     

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.     

烯丙基酚氧树脂/双马来酰亚胺改性树脂的制备及表征

用环氧树脂和二烯丙基双酚A(DP)合成了3种新型烯丙基酚氧树脂,测试了该树脂改性双马来酰亚胺(BMI)树脂体系的力学性能和热性能及黏度特性,探讨了后处理对改性树脂性能的影响。结果表明,改性树脂具有良好的2韧性和耐热性,冲击强度达到了22.31kJ/m,HDT仍有224℃,后处理使得体系耐热性大大提高,韧性略有降低。     

Near-infrared reflectance measurement of moisture,protein and oil content of ground crambe seed

Crambe moisture, protein and oil percentages were predicted by fixed-filter near-infrared reflectance with standard errors of prediction (SEP) of 0.26, 0.59 and 0.86 percentage points, respectively. Crambe had a large range of protein and oil percentages, 17.4%–25.0% and 17.7%–36.4% respectively. Calibration samples were selected on the basis of relative spectral data, with no advance knowledge of protein and oil content. This procedure selected samples representing the full range of constituent values, and resulted in calibrations that had lower SEP's than standard errors of calibration.     

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.     

Blends of bismaleimide resins and bis(allyl phenyl) esters

The effect of reactive diluents such as bis(4-allyl 2-methoxyphenyl) adipate (AEg), bis(4-allyl 2-methoxyphenyl) terephthalate (TEg), and bis(o-allyl phenyl) sebacate (APS) on curing characteristics and thermal behaviour of bis(4-maleimidophenyl) methane (BM) chain-extended with 4,4′-diaminodiphenyl methane (DADPM) is described. Samples containing 5, 10, 15, 20, 25, 35, and 45 wt.-% of these reactive diluents and bismaleimide resin were prepared. Addition of APS, AEg, and TEg affected the curing exotherm of bismaleimides. The thermal stability of bismaleimide decreased on addition of APS or AEg, but in presence of TEg an improvement in char yield at 800°C was observed. Glass fibre reinforced laminates fabricated from bismaleimide resin containing 10% APS exhibited interlaminar shear strength of 20.8 N/mm² and flexural strength of 541 N/mm².     

低温固化烯丙基酚氧树脂／双马来酰亚胺树脂的研究

为降低双马来酰亚胺树脂的固化温度,用2-甲基咪唑（2-MI）为烯丙基酚氧树脂／双马来酰亚胺树脂体系的固化催化剂,测试了改性树脂体系的凝胶化时间、力学性能和热性能,并探讨了催化剂含量对树脂性能的影响。结果表明,当催化剂质量分数为05％时,体系性能最佳。冲击强度为26．39kJ／m2,弯曲强度为14485MPa,热变形温度为202℃,树脂具有良好的韧性,并保持了优异的耐热性。     

Surface coatings based on water-soluble epoxy allyl ether polymer systems

Water-soluble polymers based on epoxy esters modified by partial allyl ethers of various polyhydric alcohols were prepared. These have very good hydrolytic and storage stability. The paints prepared from them performed well as primers and also exhibited moderate gloss. The effect of using melamine resin as external cross linker was also studied.     

Purification of steryl esters from soybean oil deodorizer distillate

Soybean oil deodorizer distillate (SODD) contains steryl esters in addition to tocopherols and sterols. Tocopherols and sterols have been industrially purified from SODD but no purification process for steryl esters has been developed. SODD was efficiently separated to low b.p. substances (including tocopherols and sterols) and high b.p. substances (including 11.2 wt% DAG, 32.1 wt% TAG, and 45.4 wt% steryl esters) by molecular distillation. The high b.p. fraction is referred to as soybean oil deodorizer distillate steryl ester concentrate (SODDSEC). We attempted to purify steryl esters after a lipase-catalyzed hydrolysis of acylglycerols in SODDSEC. Screening of industrially available lipases indicated that Candida rugosa lipase was most effective. Based on the study of several factors affecting hydrolysis, the reaction conditions were determined as follows: ratio of SODDSEC/water, 1∶1 (w/w); lipase amount, 15 U/g reaction mixture; temperature, 30°C. When SODDSEC was agitated for 24 h under these conditions, acylglycerols were almost completely hydrolyzed and the content of steryl esters did not change. However, study with a mixture of steryl oleate/trilinolein (1∶1, w/w) indicated that about 20% of constituent FA in steryl esters were exchanged with constituent FA in acylglycerols. Steryl esters in the oil layer obtained by the SODDSEC treatment with lipase were successfully purified by molecular distillation (purity, 97.3%; recovery, 87.7%).     

Production of phytosterol esters from soybean oil deodorizer distillates

Enzymatic esterification and supercritical fluid extraction was used to produce phytosterol esters from soybean oil deodorizer distillates. The raw material was first subjected to a two‐step enzymatic reaction; the product obtained mainly comprised fatty acid ethyl esters, tocopherols and phytosterol esters, together with minor amounts of squalene, free fatty acids, free sterols and triacylglycerols. The phytosterol esters were then purified from this mixture using supercritical carbon dioxide. Experimental extractions were carried out in an isothermal countercurrent column (without reflux), with pressures ranging from 200 to 280 bar, temperatures of 45–55 °C and solvent‐to‐feed ratios from 15 to 35 kg/kg. Using these extraction conditions, the fatty acid esters were completely extracted and, thus, the fractionation of tocopherols and phytosterol esters was studied. At 250 bar, 55 °C and a solvent‐to‐feed ratio of 35, the phytosterol esters were concentrated in the raffinate up to 82.4 wt‐% with satisfactory yield (72%).