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. 相似文献
The chemo-enzymatic epoxidation of Lallemantia iberica seed oil (LISO), a novel plant oil characterized by its exceptional high content of alpha-linolenic acid (>?60%), was developed using an immobilized lipase from Pseudozyma antarctica and hydrogen peroxide as oxidant. A statistical approach was used to study the effect of enzyme amount, temperature, time, and solvent amount on the oxirane oxygen content obtained during epoxidation. An oxirane oxygen content of 8.6 ± 0.2% corresponding to a yield of 82% was obtained under optimized conditions that were identified to be at an enzyme load of 8.2 g/mol of double bonds, a solvent amount of 56.4 wt.%, a temperature of 33 °C, and an incubation time of 17 h. In addition, the experimental investigation was combined with a techno-economic and ecological assessment gaining detailed information regarding cost structure and environmental impact for the chemo-enzymatic epoxidation of the novel plant oil. 相似文献
Summary: The novel potential epoxy resins, epoxidized soybean oil (ESO) and epoxidized castor oil (ECO), were synthesized and characterized. The cationic polymerization of ESO and ECO with a latent thermal catalyst, N‐benzylpyrazinium hexafluoroantimonate (BPH), was initiated at 80 and 50 °C, respectively. The cured ECO samples showed a higher Tg and lower coefficient of thermal expansion than those of ESO, due to the higher intermolecular interaction in the ECO/BPH system.
Relationships between ESO or ECO conversion and temperature in the polymerization with 1 wt.‐% BPH for 2 h. 相似文献
Immobilized lipase B from Candida antarctica (Novozyme 435) catalyzed the regioselective formation of ester bonds between organosilicon carboxylic diacids and a C1-O-alkylated sugar under mild reaction conditions (i.e., low temperature, neutral pH, solventless). Specifically, the acid-functionalized organosilicones reacted with the primary hydroxyl group at the C6 position of alpha,beta-ethyl glucoside during the regioselective esterification. The pure organosilicon-sugar conjugates were prepared in a one-step reaction without protection-deprotection steps and without activation of the acid groups with the integrity of the siloxane bonds. [reaction: see text] 相似文献
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 Tg, 396.9 °C T50 %, 74.89 MPa tensile strength, and 48.86 kJ m?2 impact resistance. 相似文献
The kinetics of the epoxidation reaction between metachloroperbenzoic acid (MCPBA) and poly-(trans-1,4-butadiene), (PTBD), crystals in toluene suspension was investigated in the 6–21°C range using infrared spectroscopy. Crystals of PTBD with M?n = 36,000 grown from heptane and from toluene solutions and crystals of PTBD with M?n = 5500 grown from heptane were studied. For toluene-grown crystals the total number of double bonds available for reaction increases with reaction temperature. For all preparations studied the epoxidation reaction is initially second-order—first-order with respect to [MCPBA] and first-order with respect to the concentration of the available double bonds. The second-order rate constant is found to be dependent on temperature, on molecular weight, and also on the crystal preparation conditions. The bromination of PTBD crystals was studied in CCl4 suspension at 0°C; this reaction was found to be complete within 1 hr with the fraction of double bonds brominated consistent with the epoxidation results. The IR spectra for dried mats of brominated and of epoxidized PTBD crystals were obtained: Changes in the amorphous band at 1335 cm?1 due to reaction of double bonds at crystal surfaces were observed. The results of this investigation are discussed in terms of the amorphous content of the PTBD lamellas. 相似文献
In this work new radically polymerizable triglyceride based monomers were synthesized by the reaction of epoxidized methyl oleate (EMO) and epoxidized soybean oil (ESO) with 4-vinyl benzene sulfonic acid (4VBSA). The products are 1-(4-vinylbenzene sulfonyl)oxy-2-alkonols of epoxidized soybean oil (SESO) and 1-(4-vinylbenzene sulfonyl)oxy-2-alkonols of epoxidized methyl oleate (SEMO). These adducts were characterized by 1H NMR, 13C NMR, IR and CHNS elemental analysis. SESO was found to contain, on the average, 2.47 4VBSA units per triglyceride. SESO was free radically polymerized and co-polymerized with styrene and the mechanical and thermal properties of the resulting thermosets were determined by DMA, DSC and TGA. SEMO was used as a model compound to determine the efficiency of metathesis catalysts for these fatty acid derivatives. The second generation Hoveyda–Grubbs catalyst was found to give best yields. ADMET polymerization of SESO with this catalyst with and without solvent gave ∼80% yield of a thermoset polymer. Polymers obtained by free radical route swelled in water at room temperature, and hydrolyzed in water at 60 °C. 相似文献
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. 相似文献
Ordered mesoporous silica material was synthesized from a low-cost precursor, sugarcane leaf ash, was used as a support matrix for lipase for the production of biodiesel. The mesoporous samples were characterized using Fourier transform infra red spectroscopy. The surface topography and morphology of the mesoporous materials were studied using scanning electron microscope. The pore diameter, pore volume, Brunauer Emmett and Teller surface area of the mesoporous material were determined by N2 gas adsorption technique. Different pore size Santa Barbara Acid-15 (SBA-15) samples were synthesized and their lipase immobilization capacity and specific enzyme activity of immobilization lipase were determined and compared. Lipase from Candida Antarctica immobilized on SBA-15 (C) had shown maximum percentage immobilization and specific enzyme activity. The immobilized lipase mesoporous matrix was used for biodiesel production from crude non-edible Calophyllum inophyllum oil. The percentage yield of fatty acid methyl ester, 97.6 % was obtained under optimized conditions: 100 mg of lipase immobilized on SBA-15, 6:1 methanol to oil molar ratio, the reaction of 2 g C. inophyllum oil with methanol. 相似文献
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. 相似文献
In the present study, castor oil (CO) was modified by epoxidation, transesterification, and acrylation processes. In situ epoxidation method was used to prepare epoxidized castor oil (ECO) in acetic acid with hydrogen peroxide in the presence of Seralite SRC-120 catalyst. Transesterified epoxidized castor oil was synthesized from the reaction of methanol in the presence of sodium methoxide catalyst. The acrylated epoxidized castor oil was synthesized from the reaction of ECO with acrylic acid containing hydroquinone. Chemical structures of modified CO were analyzed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectra analysis. 相似文献
Liquid-liquid equilibria (LLE) data were measured for ternary system epoxidized soybean oil (ESO) + acetic acid + water at 313.15, 323.15 and 333.15 K, respectively. The consistency of the measured LLE data was tested, using Othmer-Tobias correlation and root-mean-square deviation (sigma) in mass fraction of water in the lower phase and average value of the absolute difference (AAD) between experimental mass fraction of epoxidized soybean oil in the upper phase and that calculated using Othmer-Tobias correlation. 相似文献
Polyurethane (PU) solutions were synthesized with hydroxyl‐terminated polybutadiene (HTPB), 4,4′‐dicyclohexylmethane diisocyanate (H12MDI) and 1,4‐butanediol (1,4‐BD). PU membranes were prepared by dry/wet method from PU solutions, while epoxidized membranes were prepared by dipping the dried PU membranes into a mixture of formic acid and hydrogen peroxide for the reaction with C=C double bonds of HTPB soft segments. The extent of epoxidized reaction, which forms epoxide or ether groups, on the PU membranes was quantified by the absorbance ratio of the epoxide group to the butadiene group (Aepoxide/AC=C ratio). Effect of epoxidized time on the polymer composition, morphology, and polarity of these HTPB‐based PUs was investigated by FTIR‐ATR, DMA and contact angle meter. Both permeabilities and permselectivity of a water/ethanol mixture, which is measured by pervaporation method, were improved through the epoxidation of PU membranes. 相似文献
Summary: The use of renewable raw materials in the polymer industries is becoming increasingly popular because of environmental concerns and the need to substitute fossil resources. Plant oils with triglyceride backbones can be chemically modified and used to synthesize polymers from renewable resources (biopolymers). In the present study, linseed oil was epoxidized using a chemo-enzymatic method based on Candida Antarctica lipase B (CALB) as a biocatalyst and the modified linseed oil was cured using maleinated linseed oil and a commercial polyamide resin. The amount of epoxidation achieved depended on the amount of lipase used and was determined by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies. With 20% (weight per weight) catalyst concentration based on the wt % of oil a degree of epoxidation of > 90% was achieved. The cross-linking reaction of epoxidized linseed oil with the maleinated linseed oil and the polyamide resin was studied using differential scanning calorimetry (DSC). DSC traces showed that an increase in epoxidation degree lead to larger values for the exothermic enthalpy integrals of the curing reactions and hence to a higher reactivity of the linseed oil towards the cross-linking agents. 相似文献
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. 相似文献