乙二醇单丁醚为溶剂制备共轭亚油酸的研究

以乙二醇单丁醚作为溶剂,KOH作催化剂,碱催化异构化法用豆油制备共轭亚油酸。通过正交设计,紫外光谱分析考察了4种因素对亚油酸转化率的影响,并得出制备高亚油酸油脂合适的工艺条件:反应温度135℃,反应时间3 h,强碱催化剂与原料质量比为0.4∶1,原料与溶剂质量比为2∶3。在此条件下,亚油酸的平均转化率达到96.8%。结果表明,该溶剂能使反应在均相体系中较为温和的温度条件下较短的时间内完成。     

乙二醇单丁醚为溶剂制备共轭亚油酸的研究

以乙二醇单丁醚作为溶剂,KOH作催化剂,碱催化异构化法用豆油制备共轭亚油酸.通过正交设计,紫外光谱分析法考察了4种因素对亚油酸转化率的影响,并得出制备高亚油酸油脂合适的工艺条件:反应温度135℃,反应时间3 h,强碱催化剂与原料质量比为0.4:1,原料与溶剂质量比为2:3.在此条件下,亚油酸的平均转化率超过96%.结果表明,该溶剂能使反应在均相反应体系中较为温和的温度条件下较短的时间内完成.     

天然植物油碱性异构为共轭亚油酸的制备条件优化

采用KOH为催化剂,丙二醇为溶剂,天然植物油为原料,碱性异构法转化为共轭亚油酸。根据二次正交组合实验设计,研究了反应温度、反应时间、天然植物油用量等诸因素的一次、二次及其交互作用对共轭亚油酸选择性的影响,得到相应数学模型和适宜的制备条件:当m(丙二醇)∶m(KOH)=3∶1,搅拌速度500r min时,氮气保护,最适反应温度173 5℃,最佳反应时间2 85h,最优配方m(天然植物油) m(KOH)=1 55,此时共轭亚油酸的选择性≥93 6%。     

红花油制取共轭亚油酸的研究

以新疆克拉玛依厂的红花油为原料,以丙三醇为溶剂,在KOH的碱性催化作用下,将红花油先转化成亚油酸钾;再利用异构化反应制得浅黄色的共轭亚油酸产品。对产品进行了薄层层析法和紫外分光光度法定性分析,并定量分析了红花油异构化反应的程度。本研究对红花油的深加工将起到很好的推动作用。     

酯交换法合成共轭亚油酸三甘酯

采用酯交换反应,以共轭亚油酸乙酯、甘油为原料,脂肪酸钾为均相化试剂,无水K2CO3为催化剂,在压力～1 0kPa下反应制得共轭亚油酸三甘酯。合成工艺条件:n(共轭亚油酸乙酯)∶n(甘油)=6∶1;酯化反应温度140℃;反应时间～1 5h;无水K2CO3用量为共轭亚油酸乙酯质量的0 5%～1%;按统计平均值,产物三甘酯脂肪酸侧链中w(共轭亚油酸)>80%;产率(以甘油计)60%～65%。     

共轭亚油酸锌的合成工艺研究

通过利用共轭亚油酸的弱酸性质,将共轭亚油酸制成盐,以期生理功能的改变,本文利用具有生物功能活性的共轭亚油酸,先与氢氧化钠反应得到共轭亚油酸的钠盐溶液,再加入氯化锌溶液得到共轭亚油酸锌盐,平均收率为67%。为共轭亚油酸锌制成制剂的进一步研究提供了原料。     

共轭亚油酸乙酯的合成

采用间歇式反应 ,以硫酸、磷酸、对甲苯磺酸为催化剂对共轭亚油酸乙酯进行了合成 ,并采用正交实验设计研究了物料比、反应温度、反应时间、催化剂用量对产品收率和品质的影响。硫酸、对甲苯磺酸催化活性佳 ,磷酸催化活性差。得到了如下合成工艺条件 :硫酸催化 ;n(共轭亚油酸 )∶n(无水乙醇 ) =1∶6;酯化反应温度 76℃ ;反应时间 1h ;催化剂用量为共轭亚油酸质量的 2 5 % ,收率可达 75 % ,产品w(共轭亚油酸乙酯 ) =77%～ 82 %。     

新疆地产植物油碱异构化合成共轭亚油酸研究

以新疆地产植物油为原料,对碱异构化制备共轭亚油酸进行探讨。首先以棉籽油为原料,研究了溶剂用量、碱用量、反应时间和反应温度对碱异构化制备共轭亚油酸的影响,通过单因素实验和正交实验确定了最佳条件:溶剂与油质量比1.6:1、碱与油质量比0.4:1、反应时间1.5h、反应温度180℃。在此条件下,棉籽油的异构化转化率可以达到80%以上。此外,在上述得到的最优条件下对新疆产的其它植物油进行的初步尝试,发现菜籽油和葵花油的转化率较高,分别可以达到83.9%和75.2%,而红花油的转化率也可以达到57.4%。     

C22-二元酸单甲酯的合成

以棉籽油甲酯为原料,将非共轭的亚油酸甲酯在催化剂作用下转化共轭亚油酸甲酯,同时与富马酸发生Diels-Alder反应,生成C22-二元酸单甲酯,并采用正交实验设计探讨了投料比、温度、催化剂用量、反应时间对合成反应的影响。富马酸加入量按照n(富马酸)∶n(亚油酸甲酯)=1.1∶1投料,反应温度选择在200～210°C,催化剂碘的用量在0.3%(质量分数),反应控制在2h,转化率相对于亚油酸甲酯为98%。此工艺易于实现产业化。     

偏铁酸钠催化合成共轭亚油酸

以红花菜籽油中亚油酸为原料,偏铁酸钠为催化剂,在单因素试验的基础上,选取反应温度、反应时间、催化剂用量为考察因素,以异构化产物共轭亚油酸(CLA)转化率为响应值,通过响应面分析法对异构化反应进行优化,并建立相应的回归模型,试验结果表明,红花菜籽油中亚油酸异构化为CLA的最佳工艺为:反应温度195℃、反应时间4.7 h、...     

A Soap-Free Strategy for One-Pot Synthesizing Conjugated Linoleic Acid: Alkali Isomerization of Linoleic Acid through Preferential Esterification Pathway

Conjugated linoleic acid (CLA) exhibits beneficial biological activities but possesses poor natural abundance, which is usually obtained by alkali isomerization of linoleic acid (LNA). The one-pot alkali isomerization consists two reactions, firstly saponifying LNA and then isomerizing linoleate. This current process has been limited by two drawbacks, the overconsumption of both alkali and solvent, as well as the weak mass/heat transfer of the viscous paste of reaction mixture that limits the synthesis scale. The present study alternated the reaction pathway with a soap-free preferential esterification pathway, that is, firstly employing slight NaOH to induce the esterification of LNA and diol (the reaction solvent), then conducting alkali isomerization of the intermediate alkyl linoleate instead of sodium linoleate. In this developed one-pot procedure, a CLA yield of 90% and the selectivity of the desired isomers (“c9, t11” and “t10, c12” CLA) of 82.4% were obtained; and it reduced the consumption of NaOH and the solvent by 60% and 25% comparing to the current soap pathway, respectively; Yet the result is comparative to that obtained with assistant of microwave/ultrasound in even longer reaction time. In this way, the two drawbacks can be overcome and the green characteristics of the current process was well kept.     

Reactions of conjugated fat acids

Summary 1. Addition products of ethyl crotonate and crotononitrile with conjugated methyl linoleate, derived from soybean methyl esters conjugated with a nickelcarbon catalyst, were prepared. 2. The addition product of ethyl crotonate and nonconjugated methyl linoleate was prepared and compared with that from conjugated methyl linoleate. 3. The addition product of ethyl crotonate and conjugated methyl linoleate was saponified to a dibasic acid which was used to prepare a decamethylene glycol polyester and an ethylene diamine polyamide. 4. The compatibility of the addition product of ethyl crotonate and conjugated methyl linoleate with various synthetic resins was determined. One of the laboratories of the Bureau of Agricultural and Industrial Ohemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Reactions of conjugated fatty acids. VIII. Dibasic acids by hydrogenation and oxidative cleavage

Summary Conjugated linoleic acid can be hydrogenated as sodium soap in an aqueous or ethylene glycol solution with commercial nickel catalysts. Under suitable conditions the acid is reduced predominantly to monounsaturated acids with only a slight increase in saturated acids. An alkali-conjugation reaction mixture may be hydrogenated without isolating the conjugated acids. One set of conditions found suitable for hydrogenation is as follows: 10 g. of conjugated linoleic acid, 7 g. of sodium hydroxide, 250 ml. of water, and 0.05 g. of nickel placed under 40 p.s.i. hydrogen pressure and heated at 140°C. for 1 hour. Acids prepared from this reaction mixture have an iodine value of about 90. Oxidation and chromatographic analyses of the resultant dibasic acids indicate that with alkali-conjugated linoleic acid, 1,2, 1,4, and 3,4 addition of hydrogen take place with equal ease. The reduced acids contain 66%trans acids. Withtrans,trans conjugated linoleic acid, 1,4 addition takes place to a greater extent that 1,2 and 3,4 addition, and the reduced acids are allrans. Presented at the fall meeting, American Oil Chemists' Society, Cincinnati, O., September 30–October 2, 1957. Part VII is in press, Journal of Organic Chemistry.     

Conjugation of polyunsaturated fats with dimsylsodium

The conjugation of polyunsaturated fatty esters, including soybean oil, trilinolein, soybean methyl esters, and methyl linolenate and linoleate, with the sodium salt of dimethyl sulfoxide (dimsylsodium) as catalyst has been investigated. Methyl esters are ca. 95% conjugated within 2 hr. Glycerides react more slowly but are similarly conjugated within 24 hr. The glyceride linkages are not destroyed as they would be with aqueous or alcoholic alkali. Highly conjugated oils can thus be prepared. ARS, USDA.     

C_(22)-三元酸三酯的合成

C22-三元酸三酯的合成以棉籽油甲酯为原料,将非共轭的亚油酸甲酯在催化剂作用下转化成共轭亚油酸甲酯,同时与富马酸二酯发生D iels-A lder反应,生成C22-三元酸三酯。采用正交实验设计探讨了C22-三元酸的甲基二异戊酯的投料比、温度、催化剂用量、反应时间对合成反应的影响。富马酸二酯加入量按照富马酸二酯∶亚油酸甲酯(摩尔比)=1.1∶1投料,反应温度选择在200~210℃,催化剂碘的用量在0.6%,反应控制在2 h,最佳转化率相对于亚油酸甲酯可达96%。     

Alkali-isomerized linoleic acid

Summary Alkali-isomerized linoleic acid and its methyl ester have been found to have boiling points higher than the corresponding normal C₁₈ acids and esters. By careful fractional distillation of methyl esters of alkali-isomerized C₁₈ cottonseed acids, methyl linoleate of 95% or more purity is obtained consisting of 75% conjugated methyl linoleate and some 20% of methyl ester of an altered linoleic acid. Paper No. 69, Journal Series, Research Department, General Mills, Inc. (Presented at the 19th Annual Fall Meeting of the American Oil Chemists’ Society, Nov. 7–9, 1945, in Chicago, Ill.)     

Isomerization during hydrogenation. III. Linoleic acid

Summary The isomerization that takes place during the catalytic hydrogenation of linoleic acid and methyl linoleate producescis andtrans 9, 10, 11, and 12 monoenes. The double bond at the 12 position appears to hydrogenate slightly faster than that in the 9 position. More octadecenoic acids with double bonds at the 10 or 11 positions are produced during a selective (high temperature, low pressure) hydrogenation than during a non-selective process. Although the degree of selectivity of the hydrogenation is determined by the amount of isomerization of the original pentadiene system to a conjugated diene, only part of the methylene-interrupted diene goes through this type of isomerization even during a highly selective hydrogenation. The half hydrogenation-dehydrogenation reaction mechanism is applied to explain the simultaneous positional and geometrical isomerizations.     

共轭亚油酸钠胶束的自交联行为研究

以高纯度天然亚油酸为原料,通过碱催化异构化反应制得一种阴离子可聚合脂质——共轭亚油酸钠。在水溶液中使共轭亚油酸钠分子自组装成球状胶束,再经自由基引发剂引发胶束内部共轭亚油酸钠分子间自交联反应,最终获得共轭亚油酸钠的球状自交联胶束。探索了引发剂种类和用量、反应时间和温度等因素对共轭亚油酸钠分子自交联程度的影响,并采用TEM技术直观表征所获自交联组装体的形貌。结果表明,以过硫酸铵为引发剂,80℃下使pH=13的共轭亚油酸钠水溶液交联反应10 h可以得到平均粒径为20 nm的球状自交联胶束,这是一种潜在的稳定性纳米药物载体或微反应器。