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1.
Freedman Bernard Nelson Jane S. Binder R. G. Applewhite T. H. 《Journal of the American Oil Chemists' Society》1965,42(4):340-344
A convenient laboratory preparation of methyl 12-ketostearate is described. Methyl ricinoleate is converted to methyl 12-ketostearate
in 70–75% yield by Raney nickel. The type and quantity of Raney nickel have a marked influence on the yield as well as on
the time and temp required for the conversion. The reaction is not a direct isomerization as previously assumed but appears
to be a two-step process. Methyl ricinoleate is hydrogenated rapidly to methyl 12-hydroxystearate which is then dehydrogenated
slowly to the product. Hydrogenolysis of the alcohol function is a competing reaction which is minimized by the proper choice
of reaction conditions.
A laboratory of the W. Utiliz. Res. & Dev. Div., ARS, USDA. 相似文献
2.
3.
Marcel S. F. Lie Ken Jie Wilson L. K. Lam 《Journal of the American Oil Chemists' Society》1988,65(1):118-121
Concomitant ultrasonic irradiation during the Simmons-Smith reaction facilitated the cyclopropanation of ethylenic fatty esters
and triglycerides. Methyl ricinoleate furnished predominantly the corresponding hydroxy cyclopropanoid ester when the reaction
was carried out at 85–95 C under ultrasound in the presence of zinc, while a C18 furanoid fatty ester gave a novel tricyclo derivative (methyl 9,12-epoxy-9,10;11,12-dimethanooctadecanoate). 相似文献
4.
R. Agarwal A. Rauf M. Khan J. Mustafa M. Ahmad 《Journal of the American Oil Chemists' Society》1990,67(12):932-936
Chlorophenylselenenylation methodology is shown to cause cyclization of naturally occurring β- and γ-hydroxyolefinic acids.
The phenylseleno-substituted 1,4-epoxides (tetrahydrofurans) thus obtained are oxidized by m-chloroperbenzoic acid (m-CPBA).
Reaction of phenylselenenyl chloride with methyl 12-hydroxyoctadec-cis-9-enoate (methyl ricinoleate) gave methyl 9,12-epoxy-10-phenylselenenyloctadecanoate in useful yields. A similar reaction
of phenylselenenyl chloride with methyl 9-hydroxyoctadec-cis-12-enoate afforded a quantitative yield of methyl 9,12-epoxy-13-phenylselenenyloctadecanoate. Oxidation of selenium-containing
1,4-epoxy esters by m-chloroperbenzoic acid (1 equivalent) yielded the respective olefinic 1,4-epoxy esters, while 5 equivalent
m-CPBA afforded the corresponding oxirane esters of epoxytetrahydrofurans in high yields. The structure of the individual
reaction products have been established from analytical and spectral data and corroborated by a study of their mass spectra. 相似文献
5.
Siyuan Yu Jianlan Cui Xin Wang Congshan Zhong Yanru Li Jun Yao 《Journal of the American Oil Chemists' Society》2020,97(6):663-670
Castor oil and its three derivatives including methyl ricinoleate, sodium ricinoleate and ricinoleic acid were used as the raw material for alkali fusion to prepare sebacic acid. The reaction parameters including catalyst, ratio of oleochemicals/NaOH, reaction time and reaction temperature were optimized. It was found that Pb3O4 (1%) showed the best catalytic performance, and 553 K was considered as the most suitable reaction temperature. The oleochemicals/NaOH ratios of 15:14, 15:14, 15:12 and 15:14 were determined as the optimal ratio for alkali fusion of castor oil, methyl ricinoleate, sodium ricinoleate and ricinoleic acid, respectively. In addition, the optimal reaction time of alkali fusion of castor oil was 5 hours, and that of its derivatives was 3 hours. The maximum yield in sebacic acid of 68.8%, 77.7%, 80.1%, 78.6% can be obtained by using castor oil, methyl ricinoleate, sodium ricinoleate and ricinoleic acid as the raw material, respectively. High purity of sebacic acid was confirmed by GC and melting point analysis. ICP-OES results illustrated that the content of Pb in sebcic acid was less than 1 mg kg−1. Separating glycerol from castor oil was beneficial for alkali fusion, by which, the yield of sebacic acid was increased of approximately 10%, and the reaction time was reduced from 5 to 3 hours. This study provided guiding significance for the future industrial production of sebacic acid. 相似文献
6.
Bernard Freedman R. G. Binder T. H. Applewhite 《Journal of the American Oil Chemists' Society》1966,43(7):458-460
Summary The naturally occurring, unsaturated, hydroxy fatty esters, methyl lesquerolate (methyl 14-hydroxy-cis-11-eicosenoate), methyl dimorphecolate (methyl 9-hydroxy-trans, trans-10,12-octadecadienoate), and methyl densipolate (methyl 12-hydroxy-cis,cis-9,15-octadecadienoate) have been converted to the corresponding saturated keto esters by tow routes. The unsaturated esters
were subjected to a hydrogenation-dehydrogenation reaction in the presence of Raney nickel or their saturated derivatives
were dehydrogenated by copper chromite catalysis. Yields of the keto esters are 65–82% in the nickel-catalyzed reactions,
and 71–94% by copper chromite-catalyzed dehydrogenation. In the hydrogenation-dehydrogenation system the order of reactivity
is: methyl lesquerolate>methyl dimorphecolate>methyl densipolate. Relationships between structure and reactivity of these
compounds, methyl 12-hydroxystearate, and methyl ricinoleate are discussed.
W. Utiliz. Res. Dev. Div., ARS, USDA. 相似文献
7.
Methyl oleate (18∶1) and linoleate (18∶2) were readily transformed to the correspondinggem-dichlorocyclopropane derivatives in high yield, using triethylbenzylammonium chloride as the phase-transfer catalyst in the
presence of aqueous NaOH and CHCl3. Reaction of dichlorocarbene with methyl 12-hydroxystearate furnished methyl 12-chlorostearate (49%) and 12-O-formylstearate (19%). The hydroxy group in methyl ricinoleate was protected (O-tetrahydropyran-2′-yl) prior to dichlorocyclopropanation of the ethylenic bond. Removal of the protecting group allowed the
hydroxy group to be converted to a chloride,O-acetyl, azido orO-formyl function. Treatment of methyl ricinoleate with thionyl chloride, followed by the reaction with dichlorocarbene gave
the corresponding 12-chloro-dichlorocyclopropane derivative. The dichlorocyclopropane derivative of oleic acid was transformed
to a C19 allenic fatty acid when treated witht-butyl lithium. However, the remaining dichlorocyclopropane derivatives, containing an additional functional group in the
alkyl chain, failed to yield the corresponding allenic derivatives. All derivatives were characterized by a combination of
spectroscopic and chromatographic techniques, including infrared,1H nuclear magnetic resonance (NMR), and13C NMR spectroscopy. 相似文献
8.
Palm oil contains high concentrations of carotenoids and tocopherols that can be recovered by first converting them to methyl
esters and then applying membrane technology to separate the carotenoids from the methyl esters. Several solvent-stable nanofiltration
membranes were investigated for this application. Flux with a model red palm methyl ester solution ranged from 0.5 to 10 Lm−2h−1, and rejection of β-carotene was 60–80% at a transmembrane pressure of 2.76 MPa and 40°C. A multistage membrane process was
designed for continuous production of palm carotene concentrate and decolorized methyl esters. With a feed rate of 10 tons
per hour of red palm methyl esters containing 0.5 gL−1 β-carotene, the process could produce 3611 L·h−1 of carotene concentrate containing 1.19 gL−1 carotene and 7500 Lh−1 of decolorized methyl esters containing less than 0.1 gL−1 β-carotene. The economics of this process is promising. 相似文献
9.
The formation and growth rates of dispersed carbon particles were determined experimentally for pyrolysis of ethylene, benzene,
and naphthalene in a reflected shock wave at temperatures of 1920–2560 K and hydrocarbon concentrations in argon of 1.8–20%.
The diameter of the particles formed was estimated (30–600 Å). The maximum rate of particle formation at various temperatures
[(0.7–96) · 1016 cm−3·sec−1] and the particle growth rate (0.002–0.036 cm · sec−1) were determined from results of measurements of reaction (residence) times. For pyrolysis of benzene, the activation energy
of the overall process of particle formation is 410 kJ/mole, and for all hydrocarbons studied, the activation energy of the
overall process of particle growth is 5–50 kJ/mole. The surface average particle diameter increases with increasing concentration
of the initial hydrocarbon at a constant temperature.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 4, pp. 82–89, July–August, 2007. 相似文献
10.
G. Silverstone 《Journal of the American Oil Chemists' Society》1967,44(3):191-193
Filtrol 13 may be used to dehydrate methyl ricinoleate with simultaneous dimerization and polymerization of the linoleate
esters formed. Hydrolysis of the ester group is avoided by the use of xylene as an azeotroping solvent and the preferred method
of reaction is the dropwise addition of the ester to a stirred suspension of catalyst in xylene. Products prepared by this
technique had a dimer/polymer ratio of about 5 when the yield was 50%. The acid value of the polymer was 7 and of the recovered
monomer 3–4. 相似文献
11.
以可再生资源蓖麻油制备的蓖麻油甲酯、己二酸、乙二醇为原料,钛酸四正丁酯为催化剂,经酯化、缩聚合成蓖麻油酸基聚酯多元醇,考察了反应时间、催化剂、蓖麻油甲酯对聚酯多元醇热稳定性能的影响,采用凝胶色谱(GPC)、红外光谱仪(IR)、示差扫描量热仪(DSC)对蓖麻油酸基聚酯多元醇的相对分子质量、结构、热稳定性进行了系统的表征。实验表明,在醇酸(己二酸∶乙二醇)比为1.15、催化剂质量分数0.04%~0.05%、温度180℃,真空缩聚2h的条件下,制得相对分子质量为2600~3800、分布指数(PDI)为1.89~2.44的不同蓖麻油酸含量的聚酯多元醇,蓖麻油酸基聚酯多元醇的熔点随着蓖麻油酸含量的增加而降低。 相似文献
12.
Koen F. Muilwijk Paul C. J. Kamer Piet W. N. M. van Leeuwen 《Journal of the American Oil Chemists' Society》1997,74(3):223-228
A series of hydroformylation experiments was performed with a high-grade and a technical-grade-derived methyl oleate (MO)
and a rhodium catalyst modified by the bulky tris(2-tert-butyl-4-methylphenyl)phosphite. In the hydroformylation of pure methyl oleate, relatively high turnover numbers were obtained
(400–500 mol/mol/h) under mild conditions (molar ratio MO/Rh=910, 80–100°C and 20 bar; CO/H2=1:1, solvent toluene), leading to about 95% conversion in 3 h. Fast isomerization occurs under these conditions to produce
the trans oleate. Trans oleate reacts more slowly than cis oleate. At temperatures below 50°C, isomerization does not occur. The use of technical-grade methyl oleate, containing 14%
9,12 diene, methyl linoleate (ML), results in lower reaction rates because dienes form stable π-allylic intermediates, which
slowly undergo hydroformylation. More severe conditions were applied to obtain higher rates. The rate varied from 50 to 400
mol/mol/h, depending on conditions (molar ratio MO/Rh=910, T=50–120°C, P = 50–80 bar; CO/H2=1:1–1:6, solvent, toluene). Several isomers of ML were formed during the reaction. Subsequent hydroformylation of these isomers
results in a complicated mixture of products. The product mixture consists predominantly of methyl formylstearate, methyl
formyloleate, methyl diformylstearate, and some yet unidentified side products. A comparison of the classic triphenylphosphine-modified
catalyst and the bulky phosphite-modified catalyst has shown that the latter is several times more active. 相似文献
13.
In this study it is shown that the epoxide derivative of oleic acid, methyl 9,10-epoxyoctadecanoate, is readily hydrolyzed
to a diol when exposed to a commercial preparation of neutral alumina. Comparison of 1H and 13C NMR spectra of the diol with those of standards showed that the product was the threo isomer. When methyl 9, 10–12,13-diepoxyocta-decanoate was treated with alumina, a mixture of dihydroxy-tetrahydrofuran regioisomers,
methyl 9,12-epoxy-10,13-dihydroxystearate and methyl 10,13-epoxy-9,12-dihydroxystearate, was obtained. These results show
that alumina is an unsuitable support for epoxidation catalysts. However, alumina-catalyzed hydrolysis of fatty epoxides is
an efficient way to synthesize polyhydroxy materials, and these materials are suitable for several industrial applications. 相似文献
14.
Kinetics of transesterification of palm-based methyl esters (POME) with trimethylolpropane (TMP) to polyol esters was investigated.
A kinetic model of reaction was obtained by assuming a series of irreversible elementary reactions at various temperatures.
The reaction rate constants were determined under limited conditions. The optimal ratios for k
2/k
1 and k
3/k
1 were 0.70–0.80 and 0.21–0.25, respectively. Both palm oil methyl esters (PPOME) and palm-kernel oil methyl esters (PKOME)
were reacted with TMP by using sodium methoxide as catalyst. The POME-to-TMP molar ratio and catalyst weight percentage were
held constant at 10∶1 and 0.4%, respectively. The effects of temperature (70–110°C) and raw materials (PKOME and PPOME) were
investigated and found to have a significant impact on the reaction kinetics. When using a large excess of POME and continual
withdrawal of methanol via vacuum, the reaction reached completion in less than 20 min at 80°C. After removal of unreacted POME, the final product contained
apprximately 98 wt% triesters. 相似文献
15.
Biodiesel production by the transesterification of cottonseed oil by solid acid catalysts 总被引:2,自引:0,他引:2
Chen He Peng Baoxiang Wang Dezheng Wang Jinfu 《Frontiers of Chemical Engineering in China》2007,1(1):11-15
Methyl esters (biodiesel) were produced by the transesterification of cottonseed oil with methanol in the presence of solid
acids as heterogeneous catalysts. The solid acids were prepared by mounting H2SO4 on TiO2 · nH2O and Zr(OH)4, respectively, followed by calcining at 823K. TiO2-SO4
2− and ZrO2-SO4
2− showed high activity for the transesterification. The yield of methyl esters was over 90% under the conditions of 230°C,
methanol/oil mole ratio of 12:1, reaction time 8 h and catalyst amount (catalyst/oil) of 2% (w). The solid acid catalysts
showed more better adaptability than solid base catalysts when the oil has high acidity. IR spectral analysis of absorbed
pyridine on the samples showed that there were Lewis and Br?nsted acid sites on the catalysts.
Translated from The Chinese Journal of Process Engineering, 2006, 6(4): 571–575 [译自: 过程工程学报] 相似文献
16.
Frank C. Naughton 《Journal of the American Oil Chemists' Society》1974,51(3):65-71
The presence of a hydroxyl group, in addition to an olefinic linkage, in the predominating fatty acid of castor oil gives
this vegetable oil many unique and interesting properties. Castor oil consists largely of glycerides of ricinoleic acid or
12-hydroxy octadecenoic acid. The chemical reactions of castor oil, undecylenic acid, 12-hydroxylstearic acid, sebacic acid,
and nylon 11, depict the uniqueness of this agricultural oil. By dehydration, castor oil is converted to a conjugated acid
oil similar to tung or oiticica oil. The catalytic dehydration results in the formation of a new double bond in the fatty
acid chain. The dehydrated castor oil imparts good flexibility, rapid dry, excellent color retention, and water resistance
to protective coatings. The pyrolysis of castor oil cleaves the molecule to produce undecylenic acid and heptaldehyde. The
pyrolysis of the methyl ester at 450–550 C results in the formation of methyl 10-undecylenate. Hydrolysis of the methyl ester
gives 10-undecylenic acid. Hydrogen bromide is added to form 11-bromo undecanoic, which is ammoniated and condensed to form
a nylon polymer. When castor oil is added slowly to an 80% caustic solution, the sodium ricinoleate formed splits to form
sodium sebacate and capryl alcohol. Sebacic acid is condensed with hexamethylene diamine to form nylon 6,10. The commercial
application of castor oil derivatives in urethanes, starch gel modifiers, medium chain triglycerides, and thixotropic additives
is reviewed briefly.
One of 12 papers presented in the symposium “Novel Uses of Agricultural Oils” at the AOCS Spring Meeting, New Orleans, April
1973. 相似文献
17.
In the presence of an immobilized lipase fromCandida antacrtica (Novozym 435R) fatty acids are converted to peroxy acids by the reaction with hydrogen peroxide. In a similar reaction, fatty acid esters
are perhydrolyzed to peroxy acids. Unsaturated fatty acid esters subsequently epoxidize themselves, and in this way epoxidized
plant oils can be prepared with good yields (rapeseed oil 91%, sunflower oil 88%, linseed oil 80%). The hydrolysis of the
plant oil to mono- and diglycerides can be suppressed by the addition of a small amount of free fatty acids. Rapeseed oil
methyl ester can also be epoxidized; the conversion of C=C-bonds is 95%, and the composition of the epoxy fatty acid methyl
esters corresponds to the composition of the unsaturated methyl esters in the substrate.
Based partly on a lecture at the 86th AOCS Annual Meeting & Expo, San Antonio, Texas, May 7–11, 1995. 相似文献
18.
Gerhard Knothe 《Journal of the American Oil Chemists' Society》2001,78(10):1025-1028
Biodiesel, defined as the alkyl esters (usually methyl esters) of vegetable oils, is miscible with conventional diesel fuel
at all blend levels. Until the present time, no rapid and reliable analytical method has existed for determining the blend
level of biodiesel in conventional diesel fuel. In the present work, near-infrared (NIR) and nuclear magnetic resonance (NMR)
spectroscopies were used to determine the blend level of biodiesel in conventional diesel fuel. Several regions in the NIR
region (around 6005 cm−1 and 4800–4600 cm−1) are suitable for this purpose. The method is rapid and easy to use, and does not require any hardware changes when using
the same instrument for monitoring the biodiesel-producing transesterification reaction and determining biodiesel fuel quality.
In 1H NMR spectroscopy, the integration values of the peaks of the methyl ester moiety and the aliphatic hydrocarbon protons in
biodiesel and conventional diesel fuel were used for determining blend levels. The results of NIR and NMR blend level determinations
are in good agreement. 相似文献
19.
P. E. Sonnet M. E. Lankin G. P. McNeill 《Journal of the American Oil Chemists' Society》1995,72(2):199-204
Reaction of fatty acids with dimethyldioxirane in acetone produces ketoacids in 9–12% yields in which the ketone carbonyl
is distributed along the fatty chain. The n-1 position appears to be preferred. Lactones of hydroxy fatty acids are oxidized
by this reagent, but in low yields, to the corresponding ketoacids. Biphasic epoxidations with methylethyldioxirane in 2-butanone
were conducted with methyl oleate and methyl ricinoleate to give the corresponding expoxides in high yield, and olive oil
and tallow were cleanly epoxidized by this procedure as well. 相似文献
20.
N. M. Chernenko N. Yu. Beilina A. I. Sokolov 《Refractories and Industrial Ceramics》2009,50(2):149-152
A technology has been developed for making carbon-ceramic composite refractories by combining carbon fibers as reinforcing
component with a mixture matrix, which allows one to make refractory components of various sizes and geometry, including thin-walled
large constructions. The heat resistance of these composite refractories increases with the bulk silicization during ceramic
production on a carbon-carbon substrate. The degree of silicization is determined by the volume of the open microporosity
of transport type, which is formed by pyrolysis of a polymer coke-forming matrix in the initial carbon plastic. The transport
micropores are produced by a modification of the phenol-formaldehyde resin additive treatment, which does not give rise to
coke on pyrolysis. As a result, the content of open pores in the carbon framework attains 55%, which enables one to make a
silicized composite refractory of density up to 2.7 g/cm3 with a compressive strength of 250 – 300 MPa, bending strength 120 – 140, and tensile strength 60 – 80 MPa, elastic modulus
120 – 140 GPa, linear expansion coefficient 3.5 × 10–6 – 4.5 × 10–6 K–1, and thermal conductivity 6 – 8 W/(m ∙ K). These refractories are widely used in various branches of industry
Translated from Novye Ogneupory, No. 4, pp. 132 – 135, April, 2009. 相似文献