Cyclic fatty acid yields from linseed oil

Increased yields of saturated cyclic fatty acids which are fluid at −50C have been obtained from linseed oil. Depending on reaction conditions, yields varied from 20–42 g of cyclic acids per 100 g of linseed oil. Solvent ratios of 6, 3, and 1.5∶1; catalyst concentrations of 10, 30, 60, and 100%; and reaction temps of 225, 275, 295, and 325C were evaluated. Ethylene glycol and diethylene glycol were compared as reaction solvents. In general, high solvent ratios favored high cyclic acid yields at the lower reaction temperature, but as the temperature increased the effect of solvent ratio decreased. Increasing the percentage excess of sodium hydroxide increased the cyclic acid yield. Diethylene glycol gave higher yields than ethylene glycol at comparable conditions. Presented at the AOCS meeting in Chicago, Ill., October, 1961. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Partial hydrogenation of linseed oil by a continuous process

Summary Alkali refined linseed oil was partially hydrogenated, using both continuous and batch processes. The continuous process was carried out in a series of Votator machines, using Rufert nickel catalyst, presures up to 145 psig. and temperatures up to 400°F. The continuous hydrogenation of linseed oil under the most selective conditions possible, using the Votator equipment, shows little selectivity between the linolenic and linoleic acid radicals. A pronounced selectivity is observed between oleic and the more unsaturated acid radicals. Under selective conditions of hydrogenation of linseed oil about 31% of the hydrogenated linolenic acid radical is transformed into 9–15 linoleic acid while the remainder of the linolenic acid goes to oleic acid in either one or two steps. Batch hydrogenation yields oils of superior nonyellowing characteristics over comparable oils prepared by the continuous process. The hydrogenated linseed oils were tested in both clear and pigmented alkyds where they displayed superior non-yellowing characteristics over the original linseed oil and, in many instances, over that of soya bean oil. The yellowing of oils and alkyds appears to be a function of both 1) the quantity of fatty acids more unsaturated than oleic present in the oil and 2) the ratio of the quantity of linolenic acid radicals to linoleic acid radicals present. Presented at 21st fall meeting, American Oil Chemists' Society, Chicago, Oct. 20–22, 1947.     

亚麻油改性不饱和聚酯树脂合成工艺研究

研究了采用亚麻油改性的双环戊二烯型不饱和聚酯树脂的合成工艺。实验表明,其最佳反应条件为:一次性混合投料,加成反应温度124℃,反应时间2h,n(饱和酸)∶n(不饱和酸)为7∶93,亚麻油用量为0 06mol。应用上述工艺条件合成的树脂具有良好的气干性、柔韧性。     

The hydrogenation of dietary unsaturated fatty acids by the ruminant

Summary Goats were fed alfalfa meal containing 10% cottonseed or linseed oil. After 11 weeks the fatty acids of rumen, stomach, and caecum contents were compared to those of the feed. It was found that the high levels of linoleic and linolenic acis of the feed were reduced to very low levels in the rumen, with comparable increases in the saturated acids. Monoethenoid acids were increased after linseed oil ingestion and in one animal after cottonseed oil ingestion. The ratio of monoethenoid to saturated acids in the rumen fat was lower than in the endogenous fat of nonruminant animals. This explains the paradox of the low ratio in the depot fat of ruminants even after the ingestion of highly unsaturated fats. Supported, in part, by a grant from the Office of Naval Research. Scholar of the government of Mysore, India.     

Liquid C-18 saturated acids derived from linseed oil

Liquid C-18 saturated monocarboxylic acids that fail to crystallize at −70°C. have been prepared from linseed oil, linolenic acid, and tung oil. Heating one part of linseed oil in three parts of glycol (weight-volume ratio) at 295°C. for 1 hr. with 25% excess sodium hydroxide, followed by distillation and hydrogenation of the resulting free fatty acid monomers and separation of the straight-chain components by low temperature crystallization from acetone, yielded these liquid acids. The relative proportions of cyclic acids, straight-chain monomeric acids, and polymer varied with the type of starting material and with the conditions employed. Cyclic acids in excess of 30% yields were obtained from linseed oil. Some hydroxylation of the fatty acids apparently takes place during cyclization; the amount increases with ascending temperatures, as evidenced by a rise in polyester content of the polymer fraction. Evidence indicates that the bulk of the unhydrogenated cyclic acids are vicinal disubstituted cyclohexadienes. Gas chromatography of the cyclic acids hydrogenated to an iodine value <1 shows that there are several components. These have not as yet been separated and positively identified. Presented at fall meeting, American Oil Chemists' Society, New York, N.Y., October 17–19, 1960. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Methods for improving yields of cyclic acid from linseed oil

Liquid C-18 saturated monocarboxylic acids, which are termed “cylic acids” because they contain a ring structure, have been prepared by the action of excess sodium hydroxide on linseed oil in ethylene glycol at elevated temperatures, followed by distillation and hydrogenation of the resulting free fatty acid monomers and by separation of the straight-chain components by low-temperature crystallization from acetone. In a survey of other possible catalysts and reaction conditions, cyclic acid yields were improved from the previously reported 32.4 g to 43.5 g of cyclic acid per 100 g of linseed fatty acids by removing water from the starting materials and using the monosodium derivative of ethylene glycol as catalyst. The corresponding amount of polymer formed decreased because of a decrease in hydroxylation and subsequent polyester formation. Presented at the AOCS meeting, in Chicago, Ill., 1961. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Synthesis,characterization, and properties of isocyanate-free urethane coatings from renewable resources

Isocyanate-free urethane coatings were prepared from renewable resources through the aminolysis reaction of five-membered cyclic carbonate from linseed oil and phenalkamine from cashew nut shell liquid. The five-membered cyclic carbonate functional reactants were synthesized from epoxidized linseed oil through carbon dioxide insertion. The porous-free urethane coatings were prepared on aluminum substrates using synthesized carbonated linseed oil and phenalkamine at three different mixing ratios (1:0.5, 1:0.75, and 1:1.25) and at three different cure temperatures (60, 80, and 100°C). The formation of urethane linkages and the rate of cyclic carbonate conversion during the aminolysis reaction were characterized using FTIR spectroscopy. The thermal behavior of the cured urethane films was characterized using thermogravimetry. The effects of amine concentration and cure temperature on the optical, mechanical, and end-use properties of the coatings were evaluated by measuring specular gloss, solvent resistance, crosshatch, solvent swelling, and impact strength. The increase in cure temperature was directly proportional to the rate of aminolyis reaction and also to the coating performances.     

Experimental and numerical investigation of the reaction of 2,4-thiazolidinedione and p-methoxybenzaldehyde in microreactors for the production of drugs for diabetes mellitus type 2 treatment

The use of microreactors (MRs) in chemical and pharmaceutical industries allows for a series of advantages due to their reduced sizes regarding conventional batch reactors. In the present paper, the transposition of the reaction between 2,4-thiazolidinedione (TZD) with p-methoxybenzaldehyde from batch to a continuous capillary MR was carried out. The microdevice performance was evaluated experimentally and numerically by computational fluid dynamics (CFD). The batch process yielded 92% in 480 min using piperidine for equimolar reactant feed, while the pyrrolidine promoted a 100% yield in a 50 min, both using solvent ethanol. Kinetic and thermodynamic parameters of the synthesis using piperidine and pyrrolidine were also obtained from experimental data. In the transposition to flow chemistry, ethanol was also used as solvent and a product yield of 100% (140°C, pyrrolidine) was obtained for a residence time of 20 min, representing a reduction of 24 times in the reaction time. In the numerical simulations by CFD, two mathematical models were elaborated: a transient batch and a steady-state continuous flow. Both models exhibited good agreement with experimental data. The average relative deviations of TZD conversion and the reaction yields in MRs were, respectively, 0.23% and −7.1% (78°C) and 1.7% and 1.2% (140°C).     

Factorial evaluation of operational variables of a DAF process to improve PHC removal efficiency

A dissolved air flotation (DAF) process is used for removing oil from oil—water emulsions. Operational conditions that increase shearing and disturbance of liquid during the operation of large-scale DAF systems can significantly reduce oil removal efficiency. Objectives of this study were to evaluate the individual and interactive effects of the operational variables of the DAF process on removal efficiency of petroleum hydrocarbons from water sources contaminated with fuel oils. A series of batch and continuous experiments (utilizing full pressurization and effluent recirculation) were conducted using a 60-L DAF system which could be operated either in batch or continuous modes. The experiments were conducted as a factorial design to evaluate both the individual effects and the interactions of the operational variables which included oil concentration, detention time, water type (brackish and pond), coagulant use, and operational mode. The factorial analysis showed that for the batch mode of operation, oil concentration, detention time, coagulant use, and water type had a significant effect on PHC removal. However, for the continuous DAF runs, the only variable that was significant at the 95% confidence level was detention time. Coagulant use did not have a significant effect on PHC removal efficiency for the continuous runs due to shearing of the flocs.     

Synthesis and characterization of mono‐acylglycerols through the glycerolysis of methyl esters obtained from linseed oil

Here we investigate the production and characterization of mono‐acylglycerols through the glycerolysis of biodiesel, a methyl ester mixture, obtained from linseed oil. The biodiesel employed was derived from linseed oil through transesterification according to transesterification double step process 1 . The efficiency of H₂SO₄, CaO, and NaOH as catalysts was evaluated for the production of mono‐acylglycerols. The glycerolysis reactions were performed by varying the molar ratio of the reagents (biodiesel:glycerol), the type and amount of catalyst, reaction time and temperature. Systematic evaluation of reaction yield is shown as a function of these parameters. Reaction products were characterized through IR spectroscopy, hydrogen NMR, and the GC techniques. The study of three different catalysts indicated that the most efficient was 5% NaOH in a 1:5 biodiesel–glycerol molar ratio with 10 h reaction time. The reaction reached a maximum of 85% biodiesel conversion with a mono‐acylglycerol yield of 72% at 130°C.     

Polymerization of linseed oil in an electric discharge

Summary The treatment of linseed oil by the action of electric discharges (voltolization) in a hydrogen atmosphere (80 mm. Hg, 70°C.) is described. It has been known for a long time that voltolization of linseed oil brings about a polymerization of the oil. Now it has been proven that the nature of the polymerization product thus obtained is absolutely different from that of thermally or catalytically polymerized linseed oils. In contrast to the latter, voltolized linseed oils contain only small amounts of cyclic compounds. Their viscosity is relatively low, even at a high polymerization degree, and considerably less than that of thermally polymerized oils of a corresponding degree of polymerization. Atomic hydrogen seems to play an important part in the voltolization process. Coupling of fatty acid chains is made possible by combining radicals, formed primarily by the action of hydrogen atoms. Coupling reaction occurs almost exclusively intermolecularly. The possibility of transforming linseed oil and other drying oils into polymerization products of a completely different chemical structure, depending on the applied polymerization process, opens new possibilities for their manufacture. Compare T. Hoekstra, Thesis, Delft 1958 (in Dutch).     

过氧化氢一步法制备环氧亚麻油工艺

报道了亚麻油在以石油醚为溶剂、磷酸为催化剂的条件下,经甲酸、双氧水环氧化,一步合成增塑剂——环氧亚麻油的一种新方法。该法反应条件温和,操作方法简单,反应时间较短,而且产物各项指标均可达到增塑剂标准：环氧值＞7.8,碘值＜10,酸值＜0.5。     

Determination of cyclic fatty acids by gas-liquid chromatography

A method is described to determine cyclic fatty acids in cyclic monomers by gas-liquid chromatography (GLC), which separates saturated straight-chain esters from cyclic esters. The content of cyclic esters can be determined by integration of the area on the chromatograph under the cyclic peaks. GLC was applied to cyclic monomers made from linseed oil and from linolenic acid. Samples of both hydrogenated and nonhydrogenated cyclic monomers were analyzed; however, more reliable results were obtained on the hydrogenated samples. The results show a standard deviation of 0.25 for linseed oil and 0.36 for linolenic acid. Accuracy of the analysis was established by comparing data with that obtained by crystallization. The GLC method is approximately three times faster. Presented at the AOCS meeting, New Orleans, La., 1962. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Laboratory sulfonation methods for detergent alkylbenzenes

Laboratory methods are described for evaluation of alkylbenzenes by three different sulfonation techniques: batch oleum sulfonation, continuous oleum sulfonation, and batch sulfur trioxide-air sulfonation. Sulfonation conditions such as temp, mixing, and reaction time are carefully controlled; and the resulting sulfonates are reproducible in quality. Of particular interest is the close control of the sulfonating agent feed rate. In the batch oleum method, this is accomplished by flow through a calibrated capillary under constant head and in the SO₃-air method, by constant rate injection of liquid SO₃ into the vaporizer. In the continuous oleum method, both alkylate and oleum feed rates are kept at desired levels with a duplex positive displacement pump which pumps against spring-loaded ball check valves in the lines to the mixing pump. Sulfonation data (including solution colors and unsulfonated oil contents of the products) are presented for several commercial detergent alkylbenzenes varying in average mol wt from 241–267. Quality of the alkylbenzene is more critical for the continuous oleum and batch SO₃-air methods than for the batch oleum sulfonation.     

Comparative Study of Sterol Ester Synthesis using <Emphasis Type="Italic">Thermomyces Lanuginosus</Emphasis> Lipase in Stirred Tank and Packed-Bed Bioreactors

A comparative study was done on the production of different sterol esters using a stirred tank batch reactor (STBR) and packed bed reactor (PBR) using Thermomyces lanuginosus (Lipozyme TLIM) enzyme, a commercially immobilized lipase. Different oils were used as the sources of particular fatty acids, e.g., fish oil for n-3 polyunsaturated fatty acids (n-3 PUFA), linseed oil for alpha linolenic acid (ALnA) and mustard oil for erucic acid. Reaction parameters, such as substrate molar ratio, reaction temperature and enzyme concentration, were standardized in the STBR and maintained in the PBR. To provide equal time of residence between the substrate and enzyme in both the reactors for the same amount of substrates, the substrate flow rate in the PBR was maintained at 0.27 ml/min. Thin layer chromatography was used to monitor the reaction, and column chromatography was used to determine the product yields. Fatty acid compositions of the esters were determined by gas chromatography. The study showed that the packed bed bioreactor was more efficient than the batch reactor in sterol-ester synthesis with less migration of acyl groups.     

Cyclic fatty acids: Removal of aromatic acids formed during hydrogenation

Monomeric fatty acids derived from the alkali treatment of linseed oil at temperatures above 200C contain cyclic (1,2-disubstituted cyclohexadiene) and straight-chain fatty acids. Hydrogenation converts cyclic to liquid, saturated cyclic acids that can be recovered in a pure state by crystallization. During hydrogenation (palladium catalyst) some of the unsaturated cyclic acids form aromatic fatty acids by loss of hydrogen and under some conditions are not subsequently hydrogenated. It was necessary to establish conditions for complete hydrogenation since color and oxidative stability at high temperature are inversely related to aromatic content. Previously, the preparation of cyclic acids free of aromatic acids was by hydrogenation in the presence of a high concentration of acetic acid. A further study of reaction variables established conditions to make saturated cyclic fatty acids free of aromatic without acetic acid. Factors favoring the elimination of aromatic acids include a high catalyst concentration, high temperature and pressure, good hydrogen dispersion in the liquid and good agitation. Presented in part at AOCS Meeting, New Orleans, April 1964. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Production of oil-based binder by RAFT polymerization technique

In this study, air-blown linseed oil was styrenated by reversible addition–fragmentation chain transfer polymerization (RAFT). For this purpose, hydroperoxide groups were formed in the structure of linseed oil by blowing air through it. The oxidized oil was used as a macroinitiator in the styrenation process by RAFT technique using phenacyl morpholine dithiocarbamate (PMDC) as a RAFT agent. The obtained samples were characterized by GPC and FT-IR measurements. The effects of various parameters, such as the amount of PMDC, the number of peroxide groups, and the reaction time were investigated on polydispersity and molecular weight. For comparison, a copolymer sample was also prepared in the absence of PMDC. The film properties of all the samples were determined according to the related standards and compared. The sample obtained by the RAFT technique exhibited better film properties and a relatively narrow polydispersity, showing that the RAFT technique provides good control over the polymerization system in this study.     

Fish oil prevents change in arachidonic acid and cholesterol content in rat caused by dietary cholesterol

Rats were fed diets high in either saturated fat (beef tallow) or α-linolenic acid (linseed oil) or eicosapentaenoic and docosahexaenoic acids (fish oil) with or without 2% cholesterol supplementation. Consumption of linseed oil and fish oil diets for 28 days lowered arachidonic acid content of plasma, liver and heart phospholipids. Addition of 2% cholesterol to diets containing beef tallow or linseed oil lowered 20∶4ω6 levels but failed to reduce 20∶4ω6 levels when fed in combination with fish oil. Feeding ω3 fatty acids lowered plasma cholesterol levels. Addition of 2% cholesterol to the beef tallow or linseed oil diet increased plasma cholesterol concentrations but not when fish oil was fed. Feeding the fish oil diet reduced the cholesterol content of liver, whereas feeding the linseed oil diet did not. Dietary cholesterol supplementation elevated the cholesterol concentration in liver in the order: linseed oil > beef tallow > fish oil (8.6-, 5.5-, 2.6-fold, respectively). Feeding fish oil and cholesterol apparently reduced 20∶4ω6 levels in plasma and tissue lipids. Fish oil accentuates the 20∶4ω6 lowering effect of dietary cholesterol and appears to prevent accumulation of cholesterol in plasma and tissue lipids under a high dietary load of cholesterol.     

基于Aspen Polymer的聚酯聚合反应研究及流程模拟

通过Aspen Polymer对对苯二甲酸和乙二醇进行逐步聚合生成聚酯的反应进行了研究。并采用间歇反应器模块分析了进料比、压力、温度对反应的影响,结果表明进料比为1.2～2.0是比较合适的,低压高温有利于聚合反应的进行。但过低的压力导致较低的反应速率而使反应时间增加,过高的温度也导致副产物大幅度增加。因此选择压力为0.001～0.2MPa,温度为260～285℃,在间歇反应器内进行逐步降压和逐步升温反应,并在此基础上,设计模拟了压力逐步降低、温度逐步升高的连续生产工艺流程并进行优化。经过优化后的连续生产工艺流程最终反应器出口聚合度达到121.1。     

Preparation of fatty amide polyols <Emphasis Type="Italic">via</Emphasis> epoxidation of vegetable oil amides by oat seed peroxygenase

Prior work has shown that oat (Avena sativa) seeds are a rich source of peroxygenase, an enzyme that promotes the oxidation of carbon-carbon double bonds to form epoxides. Ground and defatted oat seeds were used as a low-cost source of peroxygenase. A systematic study of the epoxidation of i-butyl amides from linseed oil was conducted. Hexane was used as the primary component of the reaction media to eliminate the need for extraction. We found that the addition of a small amount of buffered water containing Tween 20 enhanced the epoxidation activity when using t-butyl hydroperoxide and cumene hydroperoxide as oxidants. This activity could be further enhanced by the addition of isopropyl ether. Conditions for larger-scale reactions were developed and applied to amides prepared from linseed, soybean, and canola oils. Because of enzymatic selectivity, the epoxidation of adjacent double bonds was low, and monoepoxides from the amides of oleate and linoleate predominated; the diepoxide, N-i-butyl-9,10–15,16-diepoxy-12(Z)-octadecenamide, was obtained from the amide of linolenate. The enzymatically epoxidized amides from the oils were hydrolyzed in dilute acid, and the distribution of the various classes of polyols was determined. Reflecting the high proportion of starting monoepoxides, saturated diols and diols with one double bond were the major polyols obtained from soybean and canola oils. Because linseed oil contains a high proportion of linolenate, polyols obtained from the epoxides of this oil had a major amount of the tetrol, N-i-butyl-9,10,15,16-tetrahydroxy-12(Z)-octadecenamide. In contrast, the components of polyols obtained from the hydrolysis of commercial epoxide preparations of soybean and linseed methyl esters followed by amide formation were primarily saturated diols and furan derivatives resulting from the presence of adjacent epoxide groups in these preparations.