乳清蛋白/阿拉伯胶复凝聚法制备载乙酸油酯微胶囊及其表征

油醇(十八烯醇)与乙酸酐的摩尔比为1/1.7,催化剂对甲苯磺酸用量为油醇与乙酸酐总质量的0.2%,25℃反应3h合成了昆虫性激素成分之一的乙酸油酯并对其进行了表征.以高分子电解质乳清蛋白(WP)和阿拉伯胶(GA)进行复凝聚制备聚合物微胶囊,对影响复凝聚的pH、两种电解质的配比及其浓度等因素进行了考察.结果表明在pH=3.5,WP/GA质量比1.5,WP和GA总浓度1.0%时复凝聚效果最佳.在该条件下以WP/GA为壁材对乙酸油酯进行了包覆,制备了不同壁材总浓度的载油微胶囊,对微胶囊的载油量和包覆率进行了测量.随着壁材总浓度的增大,芯材乙酸油酯包覆率呈现先上升后下降的变化趋势.用扫描电镜观察,发现制备的载乙酸油酯微胶囊大小在5～8μm并且乙酸油酯以核壳式结构的形式被包覆在微胶囊内部.     

The influence of hydrogen-bond association on the destruction of hydroperoxides in the autoxidation process of oleyl alcohol, oleic acid, and methyl oleate

The autoxidation process of oleyl alcohol, oleic acid, and methyl oleate at 40, 50, and 60 °C was considered with the special stress laid upon the mechanism of cumulating and destruction of peroxidic products. Interpretation of the observed differences was based on the hydrogen-bond association patterns.     

Phase equilibria of liquid (water + butyric acid + oleyl alcohol) ternary system

(Liquid + liquid) equilibrium (LLE) data for the ternary system of (water + butyric acid + oleyl alcohol) at T = (298.15, 308.15, and 318.15) K are reported. Complete phase diagrams were obtained by determining solubility and the tie-line data. The reliability of the experimental tie lines was confirmed by using Othmer-Tobias correlation. The UNIFAC method was used to predict the phase equilibrium data. The phase diagrams for the ternary mixtures including both the experimental and correlated tie lines are presented. Distribution coefficients and separation factors were evaluated for the immiscibility region. A comparison of the solvent extracting capability was made with respect to distribution coefficients, separation factors, and solvent-free selectivity bases for T = (298.15, 308.15, and 318.15) K. It is concluded that oleyl alcohol may serve as an adequate solvent to extract butyric acid from its dilute aqueous solutions.     

无溶剂体系脂肪酶催化合成阿魏酸油醇酯

对无溶剂体系中阿魏酸的转酯化疏水改性进行了研究,确立了减压反应器(0.001 MPa)中Novozym 435脂肪酶催化阿魏酸乙酯和油醇进行转酯化反应合成新型抗氧化剂阿魏酸油醇酯的方法.发现水活度(aw)明显影响转酯反应,阿魏酸油醇酯产率在aw＜0.01-0.75范围内随着水活度的增加而降低,推测底物阿魏酸乙酯和产物阿...     

Characteristics of the oxidation process in the oleyl alcohol-oleic acid,oleyl alcohol-methyl oleate,and oleic acid-methyl oleate systems by means of dielectric constant measurements

The investigation of the autoxidation process in the three model systems: oleyl alcohol-oleic acid, oleyl alcohol-methyl oleate, and oleic acid-methyl oleate by means of peroxide number and dielectric constant measurements were presented. The experiments were conducted at 60 °C, in the conditions of relatively lower amount of different kinds of hydrogen-bond polyassociates. One can state that in the case of the systems including oleyl alcohol it is possible to forecast the course of their autoxidation owing to the dielectric measurements.     

应用普通扫描仪作薄层色谱定量分析的初步研究

尝试应用普通扫描仪作薄层色谱定量分析。样品通过硅胶板层析展开后，用碘蒸汽显色，再用普通扫描仪记录其图像，通过图像分析技术计算出斑点中样品的量。结果表明，对油醇、油酸、月桂胺和焦谷氨酸油酯等长碳链有机化合物，样点在nmol级的范围内时计算量与实际量有良好的线性相关性。     

Synthesis of the p-toluenesulfonate of oleyl acohol under conditions of phase-transfer catalysis

The tosylation of oleyl alcohol under the conditions of phase-transfer catalysis has been studied. In this process oleyl p-toluenesulfonate of formed with a yield of up to 80%.Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, 443–445, May–June, 1988.     

Thermodynamic properties of binary mixtures containing sulfur amide: 3. Excess molar volumes of benzyl alcohol + N,N-dimethylmethanesulfinamide, + N,N-dimethylbenzenesulfinamide and + dimethyl sulfoxide

Excess volumes have been determined over the entire composition range for benzyl alcohol + N,N-dimethylmethanesulfinamide, + N,N-dimethylbenzenesulfinamide and + dimethyl sulfoxide at 303.06 and 323.21 K. The excess molar volumes are negative for all three systems, corresponding to the tendency of sulfinyl compounds to form hydrogen-bonded complexes with benzyl alcohol.     

Self Metathesis of Fatty Alcohols and Amines to Provide Monomers for Polyester and Polyamide Products

Summary: Self metathesis of oleochemicals offers a variety of bifunctional compounds, that can be used as monomer for polymer production. Many precursors are in huge scales available, like oleic acid ester (biodiesel), oleyl alcohol (tensides), oleyl amines (tensides, lubricants). We show several ways to produce and separate and purify C₁₈-α,ω-bifunctional compounds, using Grubbs 2^nd Generation catalysts, starting from technical grade educts.     

Comparison of oleyl and elaidyl isomer surfactant-counterion systems in drag reduction, rheological properties and nanostructure

Compared with quaternary ammonium cationic surfactants with saturated alkyl chains, quaternary ammonium cationic surfactants with one double-bond in their alkyl chains, when mixed with appropriate counterions (in certain molar concentration ratios, ξ), can reach much lower effective drag-reduction temperatures, while maintaining the upper drag-reduction temperature limit of the corresponding saturated drag reducing surfactant solutions. No previous study has compared the effects of cis- vs. trans-unsaturated alkyl hydrocarbon tail configurations (oleyl vs. elaidyl) trimethyl ammonium chloride cationic surfactants at different counterion/surfactant concentration ratios on micellar nanostructures, (1)H NMR spectra and on rheological and drag-reduction behavior of their solutions. Since neither pure oleyl (cis-) nor elaidyl (trans-) trimethyl ammonium chloride surfactants are commercially available, they were synthesized and their 5mM solutions with NaSal counterion at concentrations of 5mM, 7.5mM and 12.5mM were studied.     

High pressure FTIR study of intramolecular hydrogen bonding and conformation of a small peptide in solution

Effect of pressure on conformational equilibria of a small peptide N-acetyl-l-Pro-l-Leu-Gly-NH₂ in a chloroform solution has been studied by FTIR spectroscopy. Absorption in the NH stretching region was measured at pressures in the 1–1080 bar range and at 296 K, and decomposed into component bands by least-squares fitting. Intensity ratios of bands which were assigned to a hydrogen-bond-free conformer and intramolecularly hydrogen-bonded conformers with 10- and 13-membered hydrogen bonded rings, respectively, were examined as a function of pressure. It was found that the conformer with the 13-membered ring has definitely smaller partial molar volume than the other two conformers which have nearly the same volume with each other. On the basis of a simple dielectric model, we have shown that the conformer with the 13-membered hydrogen-bonded ring has a considerably large dipole moment which is consistent with the α-helical structure suggested by the previous variable-temperature FTIR study.     

Liquid phase equilibria of (water + propionic acid + oleyl alcohol) ternary system at several temperatures

(Liquid–liquid) equilibrium (LLE) data are investigated for mixtures of (water + propionic acid + oleyl alcohol) at 298.15, 308.15 and 318.15 K and atmospheric pressure. The solubility curves and the tie-line end compositions of liquid phases at equilibrium were determined, and the tie-line results were compared with the data predicted by the UNIFAC method. The phase diagrams for the ternary mixtures including both the experimental and correlated tie-lines are presented. The distribution coefficients and the selectivity factors for the immiscibility region are calculated to evaluate the effect of temperature change. The reliability of the experimental tie-lines was confirmed by using Othmer–Tobias correlation. It is concluded that oleyl alcohol may serve as an adequate solvent to extract propionic acid from its dilute aqueous solutions. The UNIFAC model correlates the LLE data for 298.15, 308.15 and 318.15 K with a root mean square deviation of 5.89, 6.46, and 6.69%, respectively, between the observed and calculated mole concentrations.     

Evaluation of the effect of Si/Mo and oil/alcohol ratios in the production of biodiesel from soybean oil

Mo-KIT-6 catalysts precursors obtained by direct hydrothermal synthesis using different Si/Mo molar ratios (10, 20, 30) were evaluated in the production of biodiesel from the transesterification of soybean oil with methanol. A 2² + 3PtCt factorial design was used to evaluate the influence of alcohol/oil and Si/Mo ratios on biodiesel yield. ANOVA statistical analysis showed that Si/Mo ratio was the most significant variable. The factorial design showed that the optimal conditions for maximizing the biodiesel yield are: using the 10_Mo-KIT-6 catalyst, and an alcohol/oil ratio of 20/1 at 150 °C for 3 h. However, using the 20_Mo-KIT-6 catalyst with an alcohol/oil ratio of 15/1 the biodiesel yield is close to the maximum, having the advantage of using a lower amount of methanol, which means that the separation of non-reacted alcohol will consume less energy.     

Hydrogenation of oleic acid over sol-gel ruthernium catalysts

The hydrogenation of oleic acid to oleyl alcohol over Ru-alumina and Ru−Sn-alumina sol-gel catalysts has been studied. It was found that, besides its hydrogenation activity, the Ru−Sn-alumina catalyst promotes thecis-trans isomerization of the unsaturated acid. This effect is used to explain some kinetic features of the system, like the high induction time observed in the formation of alcohols, and to re-examine the role of tin.     

Kinetics of esterification of the levulinic acid with n-hexanol,n-octanol,and n-decanol in the presence of dodecatungstophosphoric acid as a catalyst

Levulinic acid was esterified with n-hexanol, n-octanol, and n-decanol at 393–413 K and at molar ratios of between 3:1 and 10:1 (alcohol: acid) in the presence of the dodecatungstophosphoric acid (H₃PW₁₂O₄₀) as catalyst (0.1 wt%) to study the reaction kinetics. The results of such study are the precise form of kinetic equation, which is indispensable in design and optimization of industrial-scale chemical reactors. The authors stated that reactions were of second order and that the activation energy (E) decreased from 66 to 53 kJ/mol in the following alcohol sequence: n-hexanol > n-octanol > n-decanol.     

Esterification activity and stability of Candida rugosa lipase immobilized into chitosan

Microbial lipase from Candida rugosa immobilized into porous chitosan beads was tested for esterification selectivity with butanol and different organic acids (C2–C12), and butyric acid and different aliphatic alcohols (C2–C10). After 24 h, the acids tested achieved conversions of about 40–45%. Acetic acid was the only exception, and in this case butanol was not consumed. Different alcohols led to butyric acid conversions >40%, except for ethanol, in which case butyric acid was converted only 26%. The system’s butanol and butyric acid were selected for a detailed study by employing an experimental design. The influence of temperature, initial catalyst concentration, and acid:alcohol molar ratio on the formation of butyl butyrate was simultaneously investigated, employing a 2³ full factorial design. The range studied was 37–50°C for temperature (X₁), 1.25–2.5% (w/v) for the catalyst concentration (X₂), and 1 and 2 for the acid:alcohol molar ratio (X₃). Catalyst concentration (X₂) was found to be the most significant factor and its influence was positive. Maximum ester yield (83%) could be obtained when working at the lowest level for temperature (37°C), highest level for lipase concentration (2.5% [w/v]), and center level of acid:alcohol molar ratio (1.5). The immobilized lipase was also used repeatedly in batch esterification reactions of butanol with butyric acid, revealing a half-life of 86 h.     

Syntheses and Characterization of Polymetallosiloxanes from Silicic Acid and Metal Chlorides

Syntheses and characterization of polymetallosiloxanes by the non-hydrolysis sol-gel process using no metal alkoxides were investigated. The reaction of silicic acid (SA) with MCl₄ (M = Ti, Zr) in the molar ratios SA/MCl₄ = 0.5–3.0 using a tetrahydrofuran-methanol solvent formed polymetallosiloxane (PMS), which was insoluble in organic solvents regardless of the molar ratio. The PMS was isolated as esterified polymetallosiloxane by esterification with isopropyl alcohol for various periods, which were soluble in methanol, acetone, and tetrahydrofuran. The number average molecular weight was 1000–3200 for esterified polytitanosiloxane and 3400–11000 for esterified polyzirconosiloxane. Esterified polymetallosiloxanes had no melting point but decomposition point. The results of analytical data indicated that esterified polymetallosiloxane and/or polymetallosiloxane consisted of the main chain of Si–O–Si and Si–O–M linkage with the pendants of alkoxy, silanol, and chloro group.     

1-dicarboxymethylaminomethyl-2-hydroxy-3-naphthoic acid as a sensitive and selective fluorimetric reagent for beryllium,and for lanthanum and lutetium in presence of the other lanthanides

1-Dicarboxymethylaminomethyl-2-hydroxy-3-naphthoic acid (DHNA) forms fluorescent complexes with Al, Be, Ga, Hf, In, La, Lu, Mg, Sc, Th, Y, and Zr. The Be, La and Lu complexes have a metal : ligand ratio of 1:1. The beryllium complex shows maximal fluorescence at pH 6.8 with excitation-fluorescence maxima at 360 and 450 nm; linear calibration curves are obtained in the range 0.09–1.8 μg Be. In the presence of the calcium-EDTA complex, of 25 cations studied, only > 100-fold molar ratios of aluminium and > 10-fold molar ratios of magnesium and scandium caused interference in the determination of 0.1 μ mole of beryllium. Amongst 15 anions, > 100-fold molar ratios of phosphate, > 50-fold molar ratios of arsenate or oxalate and > 10-fold molar ratios of citrate, fluoride and tartrate caused low results. Lanthanum and lutetium can be determined at PH 10 and 370/460 nm in the range 7–28 μg even in the presence of a 3-fold molar ratio of the other lantlianides without interference.     

十二烷基伯胺盐酸盐与十二烷基聚氧乙烯硫酸钠复配体系中的表面性质

研究了十二烷基胺盐酸盐(DAC)和十二烷基聚氧乙烯硫酸钠(AES)复配体系的表面性质与胶束化行为.发现该体系在广泛的复配比例区间和温度区间内保持了极为优异的表面活性,测定了该体系的临界胶束浓度(cmc)与其对应的表面张力(γcmc)的具体值,并研究了温度、pH值和离子强度等环境因素对相关体系的影响.     

Kinetics of esterification of acetic acid with propyl alcohol by heterogeneous catalysis

Kinetic data on the esterification of acetic acid with propyl alcohol catalyzed by the ion exchange resin DOWEX MONOSPHERE 650 C have been obtained using a stirred batch reactor. It was checked if there is an influence of pore diffusion and film resistance on the reaction rate when varying reaction temperature, initial molar ratios, and amount of resin. The possible mechanisms of reaction were mathematically treated using the theories of Langmuir-Hinshelwood and Rideal-Eley. Taking the nonideal behavior of the system acetic acid, propyl alcohol, propyl acetate, and water into account, all calculations were realized with activities using the UNIQUAC-equation. By using the experimental results in a process of model discrimination the best kinetic parameter set was found out by the aid of the commercial software package SIMUSOLV. The resulting data of rate constants and the experimental determined equilibrium constants served as a basis for the calculation of the thermodynamic parameters of esterification, as reaction enthalpy, reaction entropy, and activation enthalpies. © 1996 John Wiley & Sons, Inc.