熔盐热裂解大豆油的特性研究

以大豆油为原料,在ZnCl₂-KCl熔融盐体系中考察了进料速量、载气流量、反应温度及进料量对其热裂解的影响。采用气相色谱-质谱联用仪(GC-MS)表征生物油组成。结果表明,进料速量和载气流量主要通过改变大豆油的反应停留时间影响裂解效果。当进料速率为1.2 g/min及不通载气时,大豆油停留时间较长,裂解较充分;随着温度升高,生物油得率增大,含氧化合物含量及酸值上升;随着进料量增大,生物油得率稳定在70%左右,但脱羧效果有所下降。经过催化加氢,生物油性质得到了明显的改善,组分分布与0^#柴油分布大体相似。     

Purification of phospholipase D by two-phase affinity extraction

An aqueous two-phase system of polyethylene glycol (PEG)-salt was used for purification of phospholipase D (PLD) from peanuts and carrots. Alginate, a known macroaffinity ligand for PLD, was incorporated in the PEG phase and resulted in 91 and 93% of the enzyme activity (from peanuts and carrots, respectively) getting partitioned in the PEG phase. The elution of the enzyme from alginate was facilitated by exploiting the fact that the latter can be reversibly precipitated in the presence of Ca2+. The enzyme was eluted from the polymer by using 0.5 M NaCl. Peanuts and carrots PLD could be purified 78- and 17-fold with 82 and 85% activity recovery, respectively. The purified enzyme from both sources gave a single band on sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) electrophoresis.     

Curing behavior of epoxidized soybean oil with biobased dicarboxylic acids

In this study, we report the curing of ESO with biobased dicarboxylic acids (DCAs) with different carbon chain-lengths to synthesize fully sustainable polymers. Both non-isothermal and isothermal curing processes analysis indicated that the curing rate and activation energy decreased with increasing chain-length of DCAs. The optimum COOH/epoxy molar ratio is 0.7 for preparation of ESO/DCA cured product with maximum degree of crosslinking. Addition of 4-N, N-dimethylaminopyridine (DMAP) as a catalyst can efficiently accelerate the curing rate and reduce activation energy. We systemtically studied the effect of chain-length of DCAs on the physical properties of cured products, and found that with increase in chain-length of DCAs, the glass transition temperature of the cured ESO/DCA decreased, the tensile strength and Young's modulus increased while elongation at break decreased, due to the decreased crosslinking density resulted from the increased chain-length between crosslinking sites. All cured ESO/DCA showed excellent thermal stability with initial decomposition temperature of higher than 340 °C.     

Thermal analysis of soybean oil based polyols

Soybean oil based polyols (5-OH polyol, 10-OH polyol and 15-OH polyol) were synthetised from epoxidized soybean oil. The melting peak of polyols and the relationship between melting peak and the number-average functionality of hydroxyl in polyols were investigated by differential scanning calorimetry (DSC). The thermal decomposition of polyols and some of their thermal properties by thermogravimetry (TG) and derivative thermogravimetry (DTG) were also studied. The thermal stability of polyols in a nitrogen atmosphere was very close hence they had a same baseplate of triglyceride for polyols. The extrapolated onset temperature of polyols in their thermal mass loss, first step had a decreasing order: 5-OH polyol>10-OH polyol>15-OH polyol due to the difficulty in forming multiple elements ring of them had the same order. The thermal behavior of polyols under non-isothermal conditions using Friedman’s differential isoconversional method with different heating rates indicated that the 5-OH polyol had the lowest activation energy in thermal decomposition amongst these polyols according to the same fractional mass loss because of the weakest intramolecular oligomerization. The 15-OH polyol was prior to reach the mass loss region because the six-member ring is more stable than the three-member ring from 10-OH polyol and more easily formed.     

Biodiesel from soybean oil,castor oil and their blends

Even not being described in the EN 14112 standard, PDSC has been used for the determination of the biodiesel oxidative stability, by OIT and OT measurements. In this study, biodiesel blends were obtained by mixing soybean (BES) and castor (BEM) ethyl esters and its induction periods were measured by Rancimat and PDSC. The blends (BSM _X ) showed intermediate values of OSI, OT, and OIT, compared with BES and BEM. Although, the molar fraction of the components varied linearly in BSM _X , OSI, OT, and OIT values increased exponentially in relation to the castor biodiesel amount in the blends. Introduction of castor oil biodiesel increased the blend stability, so the BSM₃₀ blend reached the OSI limit of 6 h. OSI, OIT, and OT showed a high-linear correlation, pointing out that PDSC can be used in the analysis of this kind of biodiesel, with a smaller sample and analysis time, as compared to Rancimat. The use of biodiesel blends was a good alternative in the correction of the oxidative stability of the final product without the need of antioxidant addition.     

Al13形态的分离纯化与表征

采用乙醇－丙酮沉淀法提取了聚合氰化铝（PAC）中的Al13形态并采用Al-Ferron逐时络合比色法、27Al NMR，SEM，TEM和XRD等方法对所获得的水溶性Al13形态进行了分析表征．结果表明，通过向聚合氯化铝溶液中不断加入乙醇和丙酮，聚合氯化铝中各形态组分便会按照在混合溶剂中溶解度由小到大的顺序，依次从溶液中析出．截取中间组分得到Al13 形态．Al-Ferron逐时络合比色法和27Al NMR的鉴定结果表明，采用该方法分离提纯得到的样品中Al13 的含量达95％以上．SEM和TEM的鉴定结果表明，固体Al13聚集体主要为棱柱、单斜长方体和四面体等多面晶粒，小的聚集体粒径约 200mm，大的可达 2μm．溶液中的Al13 形态聚集成束并以枝状排列．XRD结果表明，Al13的特征衍射峰出现在2θ为5°～25°的范围内．     

Purification of isoenzyme I of phospholipase C from Clostridium perfringens

V. I. Lenin Tashkent State University. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 888–890, November–December, 1988.     

Purification of phospholipase C by hydrophobic interaction affinity chromatography.

A simple procedure is described for the purification of phosphatidylcholine-hydrolyzing phospholipase C(PLC). Lecithin, the substrate for PLC, was ligated hydrophobically to octyl-Sepharose in 2 M (NH4)2SO4. The washed lecithin-conjugated resin was then used to purify PLC from crude preparations by affinity chromatography. PLC binds to the lecithin moiety in the presence of Zn2+ and is eluted with an acidic buffer containing EDTA. PLC activity was recovered in the eluate. Both sodium dodecyl sulphate polyacrylamide gel electrophoresis and pI electrofocusing showed that the eluate contained a single monomeric protein with an apparent molecular mass of 66 kDa and a pI of 5.5.     

Kinetics of catalytic transfer hydrogenation of soybean oil

The hydrogenation of soybean oil was studied using aqueous sodium formate solution and a palladium on carbon catalyst. All the hydrogenation reactions     

Carbonyldiimidazole‐accelerated efficient cure of epoxidized soybean oil with dicyandiamide

This study investigates the curing of epoxidized soybean oil (ESO) using dicyandiamide (DICY) and combinations of DICY with several accelerators as curing agents. The differential scanning calorimetry (DSC) results indicated that carbonyldiimidazole (CDI) is a highly efficient accelerator for the ESO‐DICY curing system. CDI accelerated ESO‐DICY curing system can gel within a short period of 13 min at 190 °C. The activation energies of the ESO‐DICY curing systems with and without CDI are 95 and 121 kJ mol^?1, respectively. Similar acceleration effect was observed in the ESO‐diglycidyl ether of biphenyl A (DGEBA) blending formulations. When the molar part of the glycidyl epoxy groups of DGEBA was equal to the internal epoxy groups of ESO in the mixture, gelation of the DICY curing system accelerated by CDI was achieved in 3 min at 160 °C. Furthermore, the DSC results with FTIR analysis suggest that the stoichiometric curing molar ratio was 3 ESO epoxy units per 1 DICY molecule. Two epoxy units reacted with DICY to give secondary alcohols, while the other one linked to the nitrile group. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 375–382     

Thermal and mechanical properties of epoxy resin toughened with epoxidized soybean oil

A series of new modified epoxy resin (EP) cured products were prepared from epoxidized soybean oil and commercial epoxy resin, with methyl nadic anhydride as curing agent and 1-methylimidazole as promoting agent. The thermal properties of the resins were characterized by DMA and TG; DSC was used to determine the curing process. Fourier transform infrared spectroscopy was utilized to investigate their molecular structures and scanning electron microscopy was used to observe the micro morphology of their impact fracture surfaces. Tensile and impact testing was employed to characterize the mechanical properties of the cured products. The combination of commercial EP with 20 wt% ESO resulted in a bioresin with the optimum set of properties: 130.5 °C T _g, 396.9 °C T _50 %, 74.89 MPa tensile strength, and 48.86 kJ m^?2 impact resistance.     

Lipase-catalyzed interesterification of soybean oil with an omega-3 polyunsaturated fatty acid concentrate prepared from sardine oil

To reduce the content of linoleoyl moiety in soybean oil, soybean oil that contains 53.0% linoleoyl moiety as molar acyl moiety composition was interesterified with an omega-3 polyunsaturated fatty acid (PUFA) concentrate (24.0 mol% eicosapentaenoic acid [EPA], 40.4 mol% docosahexaenoic acid [DHA]) prepared from sardine oil, using an immobilized sn-1,3-specific lipase from Rhizomucor miehei (Lipozyme IM). The reaction was carried out in a batch reactor at 37 degrees C under the following conditions: 500 micromol of soybean oil, molar ratio of omega-3 PUFA concentrate to soybean oil = 1.0-6.0,5.0 mL of heptane, and 30 batch interesterification units of enzyme. After the reaction time of 72 h, modified soybean oil, which contains 34.9% linoleoyl, 10.1% eicosapentaenoyl, and 14.2% docosahexaenoyl moieties, was produced at the molar reactant ratio of 6.0. In this oil, the total omega-3 acyl moiety composition reached 34.1%; the molar ratio of omega-3 to omega-6 acyl moieties was enhanced by five times compared with soybean oil. Compared with palmitic acid, DHA was kinetically six times less reactive, although the EPA was by 16% more reactive.     

Biodiesels from beef tallow/soybean oil/babassu oil blends

The aim of this work is to examine the behaviour of gutta-percha (α–β) after heating, because of the several techniques using the warm gutta-percha as root canal filling material. Samples of gutta-percha have been examined by the thermal analysis. The gutta-percha has been submitted to four runs of heating from the temperature of 25–130 °C, followed by spontaneous cooling. It was found that some products have shown the typical behaviour of the α-gutta-percha; some materials have shown characteristics similar to the conventional β-gutta-percha. The samples have shown a significant mass loss after the first run of heating, while the mass tends to stabilize after the third run. Heating of gutta-percha up to 130 °C causes physical changes; this is due to the presence of additives, which alter the behaviour of the material.     

Multivariate monitoring of soybean oil ethanolysis by FTIR

In this work, an analytical procedure was developed to monitor the ethanolysis of degummed soybean oil (DSO) using Fourier-transformed mid-infrared spectroscopy (FTIR) and methods of multivariate analysis such as principal component analysis (PCA) and partial least squares regression (PLS). The triglycerides (reagents) and ethyl esters (products) involved in ethanolysis were shown to have similar FTIR spectra. However, when the FTIR spectra derived from seven standard mixtures of triolein and ethyl oleate were treated by PCA at the region that represents the CO stretching vibration of ester groups (1700-1800 cm⁻¹), only two principal components (PC) were shown to capture 99.95% of the total spectral variance (92.37% for the former and 7.58% for the latter PC). This observation supported the development of a multivariate calibration model that was based on the PLS regression of the FTIR data. The prevision capability of this model was measured against 40 reaction aliquots whose ester content was previously determined by size exclusion chromatography. Only small discrepancies were observed when the two experimental data sets were treated by linear regression (R²=0.9837) and these deviations were attributed to the occurrence of non-modeled transient species in the reaction mixture (reaction intermediates), particularly at short reaction times. Therefore, the FTIR/PLS model was shown to be a fast and accurate method to predict reaction yields and to follow the in situ kinetics of soybean oil ethanolysis.     

Nutritional improvement of soybean oil via lipase-catalyzed interesterification

In order to decrease the content of linoleoyl moiety in soybean oil, soybean oil that contains 22.8% oleoyl, 54.8% linoleoyl, and 7.1% α-linolenoyl moieties as molar acyl moiety composition was interesterified in hexane with oleic acid or α-linolenic acid, using an immobilized sn-l,3-specific lipase (Lipozyme® IM) fromMucor miehei. The reactions were carried out in a batch reactor at 37°C in the following system: molar ratio of fatty acid to soybean oil = 1.0 ～ 6.0, 5.0 mL of hexane/500 μmol soybean oil, and 10.0 or 15.0 batch interesterification units of enzyme/500 μmol soybean oil. Under these reaction conditions, the rates of interesterification of acyl moieties in soybean oil were of the order: stearoyl > palmitoyl > linoleoyl > oleoyl > α-linolenoyl, and the reaction with oleic acid occurred without a significant loss of α-linolenoyl moiety. At the molar ratio of 3.0 and the reaction time of 6 h, triacylglycerols (TGs), which contain 50.8% oleoyl, 38.8% linoleoyl, and 5.4% α-linolenoyl moieties, were produced in the reaction with oleic acid; TGs that contain 13.5% oleoyl, 40.8% linoleoyl, and 40.4% α-linolenoyl moieties were obtained with α-linolenic acid. Approximately 86-88% of the interesterification of linoleoyl moiety, which occurred in 10 h, took place within 1 h.     

Structure and properties of partially epoxidized soybean oil

In the present study, the characteric-structure relationship of epoxidized soybean oils (ESO) with various degrees of epoxidation has been investigated. FTIR analysis was used to identify the relative extent of epoxidation of the samples during the epoxidation reaction. The viscosities of ESO were much higher than that of the raw oil, viscosity increased with degree of epoxidation. The viscous-flow activation energy of ESO was determined to be higher than that of the raw oil (20.72 to 77.93% higher). Thermogravimetry analysis (TG) of ESO was used to investigate the thermodynamic behavior of the samples. With increasing degree of epoxidation, the thermal stability of the samples initially decreased, then increased at the final reacting stage. Differential scanning calorimeter (DSC) indicated that the melting point of ESO was higher than that of soybean oil. Gel permeation chromatography (GPC) indicated the molecular mass of the samples increased initially, then decreased, with an increase in the extent of epoxidation.     

Electrorheology of chitosan polysaccharide suspensions in soybean oil

Chitosan, a biodegradable polysaccharide composed of primarily d -glucosamine repeating units, was adopted as a dry-base electrorheological fluid using soybean oil as a suspending medium. The electrorheological properties were examined under various applied electric field strengths. We found that natural organic polymers such as chitosan possessing amino polar groups induce electrorheological behavior, and the yield stress, τ_y, of chitosan increases with the electric field strength, E , according to a power-law form, τ_y∝ E ^α, which is consistent with the conduction model.     

Optimization of alkaline transesterification of soybean oil and castor oil for biodiesel production

This article reports experimental data on the production of fatty acid ethyl esters from refined and degummed soybean oil and castor oil using NaOH as catalyst. The variables investigated were temperature (30–70°C), reaction time (1–3 h), catalyst concentration (0.5–1.5 w/wt%), and oil-to-ethanol molar ratio (1:3–1:9). The effects of process variables on the reaction conversion as well as the optimum experimental conditions are presented. The results show that conversions >95% were achieved for all systems investigated. In general, an increase in reaction temperature, reaction time, and in oil-to-ethanol molar ratio led to an enhancement in reaction conversion, whereas an opposite trend was verified with respect to catalyst concentration.     

Purification and some properties of phospholipase C from Achromobacter xylosoxidans.

A non-haemolytic phospholipase C (EC 3.1.4.3) was purified from the culture medium of Achromobacter xylosoxidans with a 5% yield and a purification factor of 330. A combination of ultrafiltration, acetone precipitation and two subsequent affinity chromatographic steps was used. The affinity chromatography is a new application of 2-(4-aminophenylsulphonyl)ethyl-cellulose, a sorbent that has previously been used for the purification of phospholipase C from Bacillus cereus. The purified enzyme gave four distinct bands on polyacrylamide gel electrophoresis, and each band was catalytically active. Under our experimental conditions, the phospholipids examined were hydrolysed in the following order: phosphatidylcholine, phosphatidylethanolamine, sphingomyelin. Neither the synthetic substrate p-nitrophenylphosphorylcholine nor phosphatidylinositol was hydrolysed under different experimental conditions. For maximal hydrolytic activity toward phosphatidylcholine, the enzyme required Triton X-100 and Ca2+ ions. EDTA was inhibitory, but the enzyme activity was almost completely restored by Zn2+. The molecular mass of the phospholipase C, estimated by gel permeation, was 34,000 daltons.