聚甘油脂肪酸酯的表面性能研究

利用甘油聚合得到聚甘油,与一系列高级脂肪酸酯化合成聚甘油脂肪酸酯。分别测试和比较了合成产品的HLB值、表面张力、乳化性能、泡沫性能及钙皂分散性能,并讨论了合成影响因素,为研究聚甘油酯类产品应用性能提供了理论基础。     

Microwave‐assisted synthesis of polyglycerol from glycerol carbonate

Microwave irradiation of glycerol carbonate allows formation of glycidol, which readily polymerizes to form polyglycerol under mild conditions comparatively to the classical polyetherification reaction involving high temperature and basic conditions. Analysis of the crude reactional mixture indicated the presence of low‐molecular weight oligomers constituted mainly of di, tri, and tetraglycerols with small quantities of higher molecular weights oligomers. Molecular size distribution was relatively similar to that of polyglycerols obtained under basic condition, even if these latter contained slightly higher amounts of high‐molecular weight oligomers. Structure of oligomers differs slightly according to the conditions of polymerization, and polyglycerols are obtained under microwave activation containing higher contents of cyclic isomers, whereas polyglycerols obtained under basic conditions contain more ramified isomers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

聚异丁烯丁二酸聚甘油酯的制备及其性能研究

以聚异丁烯丁二酸酐、聚甘油为原料,制备了标题化合物,并用红外光谱对其进行结构表征。测定了产品的极限乳化性能与储存稳定性能,结果表明,产品的极限乳化性能与储存稳定性能均优于聚异丁烯丁二酰亚胺(T152),适用于乳化炸药行业;并且测定了产品的分散性能,结果表明产品的分散性能优于聚异丁烯丁二酰亚胺(T154),适用于润滑油行业。产品的成本明显低于聚异丁烯丁二酰亚胺(T152,T154)的成本,具有很好的推广前景。     

Preparation of sorbitol fatty acid polyesters,potential fat substitutes: Optimization of reaction conditions by response surface methodology

Effects of the reaction temperature, reaction time, mole ratio of fatty acid methyl esters (FAME) to sorbitol, and mole ratio of fatty acid sodium soaps (FASS) to sorbitol on yields of sorbitol fatty acid polyester (SFPE) were examined with a response surface methodology. The optimum reaction conditions selected with response surface analysis were as follows: reaction temperature, 144°C; reaction time, 6.65 h; mole ratio of FAME to sorbitol, 10.7∶1; and mole ratio of FASS to sorbitol, 0.77∶1. Under these reaction conditions, the experimental yield of sorbitol fatty acid polyester (mean value: 92% range: 89–94%) obtained from seven replications was close to the predicted value (94%) calculated from the polynomial response surface model equation. The response surface methodology approach used in this study was able to predict the reaction conditions necessary for a high yield of sorbitol fatty acid polyester.     

聚甘油脂肪酸酯类乳化剂制备乳液功效性研究

测定了聚甘油-6二硬脂酸酯、聚甘油-10硬脂酸酯、聚甘油-10二棕榈酸酯制备的乳液的粒径、皮肤水分含量、经皮水分流失TEWL.结果表明,聚甘油-6二硬脂酸酯制备的乳液分散性较好,乳液粒径分布较小;聚甘油-10二棕榈酸酯制备的乳液在皮肤水分含量、经皮水分流失TEWL值上优于其他2组.     

Oxidative stability of fat substitutes and vegetable oils by the oxidative stability index method

Oxidative Stability Index (OSI) of carbohydrate fatty acid polyesters, fat substitutes and vegetable oils were measured with the Omnion Oxidative Stability Instrument according to the new AOCS Standard Method Cd 12 B-92 (The Official Methods and Recommended Practices of the American Oil Chemists' Society, edited by D. Firestone, AOCS, Champaign, 1991). The stability of crude and refined, bleached and deodorized (RBD) vegetable oils (soybean, hydrogenated soybean and peanut) were determined at 110°C. In addition, OSI times for sucrose polyesters of soybean oil, butterfat, oleate:stearate and methyl glucoside polyester of soybean oil were determined in the absence and in the presence of 0.02 wt% antioxidants, [Tenox TBHQ (tertiary butylhydroquinone, Tenox GT-2 (from Eastman Chemical Products (Kingsport, TN); and vitamin E (from BASF, Wyandotte, MI)], and the results were compared with those of vegetable oils. Crude oils were most stable (20.4–25.9 h), followed by RBD oils (9.3–10.4 h) for soybean and peanut oils, respectively, and fat substitutes (3.8–6.8 h). Overall, Tenox TBHQ was the best antioxidant for improving the oxidative stability of both vegetable oils and fat substitutes. The sucrose polyester made with oleic and stearic acid was more stable than fat substitutes containing more polyunsaturated fatty acids, such as those from soybean oil, or from short-chain fatty acids, such as from butterfat. Antioxidants enhanced the stability of RBD oils (222% increase) and synthetic fat substitutes (421–424% increase) more than that of crude oils (33% increase). The shapes of the induction curves, not the actual OSI times for fat substitutes and vegetable oils, were similar and sharply defined.     

Convenient preparation of picolinyl derivatives from fatty acid esters

It is essential to have simple rapid methods for the determination of fatty acid structures. Traditionally, fatty acids are analysed by gas chromatography using their methyl ester derivatives (FAME). However, their corresponding mass spectra exhibit molecular ions but are usually devoid of ions indicative of structural features and, notably, the position of double bounds on the aliphatic chains [1]. In the most useful approach to structure determination, the carboxyl group is derivatised with a reagent containing a nitrogen atom. Recently, a convenient method for preparing picolinyl esters from intact lipids has been published [2]. However, some problems occurred in our laboratory when this method was used, leading to some modifications and optimisation. Thus, hexane and water have been added while sodium bicarbonate has been removed in order to lower contamination. Temperature and length of the reaction have then been optimised in order to get 100% derivatisation for different kinds of lipids (45 °C and 45 min for FAME). Finally, a comparison of the response factors has confirmed the better sensitivity of the picolinyl derivative against FAME (five times more).     

The preparation of poly(methylene esters)

Conditions are described which allow the synthesis of poly(methylene terephthalate) from the reaction of methylene bromide with caesium terephthalate and though application of the procedure to prepare polymers from aliphatic dicarboxylic acids was unsuccessful, such polymers were synthesized from the analogous reaction with bromochloromethane.     

Heated fat-based oil substitutes, oleic and linoleic acid-esterified propoxylated glycerol

Four oils [triolein, trilinolein, oleic acid-esterified propoxylated glycerol (EPG-08 oleate), and linoleic acid-esterified propoxylated glycerol (EPG-08 linoleate)], each without added antioxidants, were heated for 12 h/d at approximately 190°C in a small deep-fat fryer until the polymer concentration exceeded 20%, as determined by high-performance size-exclusion chromatography. Increases in the free fatty acid content, total acid value, food oil sensor value, and p-anisidine value during heating indicated that significant thermal oxidation had occurred in each oil. Capillary supercritical fluid chromatography (SFC) was used to determine the substrate concentration of each oil after each heating interval. The average, apparent first-order reaction rate constant (as determined by SFC) for trilinolein was 0.0348±0.0034 h⁻¹, while the rate for EPG-08 linoleate was 0.0253±0.0032 h⁻¹. The average apparent reaction rate constant for triolein was 0.0256±0.0011 h⁻¹, while the rate for EPG-08 oleate was 0.0252±0.0008 h⁻¹. Triolein contained >20% polymer after 60 h of heating, EPG-08 oleate contained >20% polymer after 36 h of heating, and both trilinolein and EPG-08 linoleate contained >20% polymer after 24 h of heating.     

Electrochemical preparation of pinacol allylboronic esters

The electroreduction of allylic halide derivatives in the presence of pinacolborane afforded allylboronic pinacol esters with moderate to good yields (up to 86%) and high regioselectivities. The electrosynthesis was carried out in a single-compartment cell with an Al anode, in THF at room temperature and it constitutes an alternative route for the preparation of allylboronic esters under mild conditions.     

Effects of polyglycerol esters of fatty acids and ethylene‐vinyl acetate co‐polymer on crystallization behavior of biodiesel

Biodiesel fuels (BDF) have many problems in the cold due to their crystallization properties. In particular, precipitation of large crystals of high‐melting fractions in BDF at low temperatures remarkably changes cold flow property of BDF and, thereby, it increases the values of cold filter plugging point. In this study, we evaluated polyglycerol esters of fatty acids (PGE) and ethylene‐vinyl acetate co‐polymer (EVA) as chemical additives to improve the cold flow property of palm oil‐based FAME (PFME). The results of solid fat content measurement indicate that the simultaneous addition of PGE and EVA showed synergistic effects on suppression of crystallization of PFME, however such effect was not observed when EVA was used alone. DSC thermograms indicated that the PGE additives not only decreased the crystallization temperature but also kinetically suppressed the crystal growth. Polarized light microscopy showed that the simultaneous addition of PGE and EVA led to the formation of considerably small and fine‐dispersed crystals of PFME. These results indicate that combined effects of PGE and EVA caused the formation of fine‐dispersed PFME crystals, which could improve the viscous properties of palm oil‐based BDF at relatively cold temperatures.     

高单酯含量蔗糖酯的无溶剂制备

通过把微细蔗糖和硬脂酸甲酯制成粗分散体系(粒径小于10μm),用无溶剂法制备出了单酯含量高达79.8%的蔗糖酯。与其他典型的方法不同,该方法仅用4%的皂就可使硬脂酸甲酯转化率超过99%,大大减少了皂的用量。而且用相同量的皂就可制备出不同单酯含量的蔗糖酯,产率最高可达62.4%。考察了这种新反应体系的温度、催化剂量、皂的量和反应时间等不同条件下硬脂酸甲酯的转化率,还测定了不同单酯含量蔗糖酯的亲水亲油平衡(HLB)值、表面张力、界面张力和临界胶束浓度,揭示了它们之间的相互关系。     

Polymerization of ethyl acrylate using hyperbranched polyglycerol with multi‐RAFT groups as chain transfer agent

Surfacing hydroxyl groups of hyperbranched polyglycerol (PG) were transformed into trithiocarbonates (TTC), an efficient multi radical addition‐fragmentation transfer (RAFT) agent, to mediate the polymerization of ethyl acrylate (EA) under controllable conditions, and PG with multiarm PEA was obtained. In this system, PG was a part of Z groups, and trithiolcarbonates were bonded directly to the PG, whereas the growing PEA macroradical was detached. The molecular weight and the molecular weight distribution of the products were in the range of 1.05–3.24 × 10⁴ g/mol and 1.28–1.42, respectively, when the concentration ratio of EA to PG‐TTC was 39.8. The number of the PEA arms was about 16. It was found that the measured molecular weights of the products were deviated from the theoretical value, and the molecular weight distribution was broadened with the conversion due to the termination between the leaving macroradicals. The final and the intermediate products were characterized by NMR in detail. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2203–2209, 2006     

Improved method for the determination of wax esters in vegetable oils

In this work, a modified International Olive Council (IOC) method for wax determination involving a double‐adsorbent layer of silica gel and silver nitrate‐impregnated silica gel is presented (SN method). Column chromatography by the SN method did not show retention of wax esters standards with an even number of carbon atoms (C34–C44), observing recovery percentages higher than 90% even for unsaturated wax esters. All wax fractions were lower by the SN method than by the IOC method, resulting in a percentage decrease in the total wax content (olive oils: 20–50%, crude sunflower oil: 38%, crude soybean oil: 58% and crude grape seed oil: 13%). Olive oils analysed by the SN method showed increases of up to 27% in C40 relative percentage with respect to the IOC method. Additionally, decreases were observed by the SN method in the relative percentages for odd‐carbon atom waxes for the seed oils in comparison to the IOC method (crude sunflower oil: 27%, crude soybean oil: 28% and crude grape seed oil: 13%). The main advantages of the proposed modification consist in its easy implementation and a better determination of wax esters (C34–C60) by controlling their complete recovery and removing interfering substances. The method is suitable for quality control and for authentication of olive oil and seed oils as well as in processing monitoring. Practical applications: The proposed method is useful in the quality, authentication and processing control of fruit and seed oils. Moreover, it can be an important tool for vegetable oil industries to control the efficiency of the wax separation process to prevent turbidity in the refined oil.     

硫代香叶酯的研制

讨论了以芳樟醇Linalool和硫代香叶醇为原料合成硫代香叶酯。并对合成硫代香叶酯的工艺条件进行优化，使硫代香叶酯的收率达到58％。     

Quality control of rapeseed oil methyl esters by determination of acyl conversion

A simple procedure for the evaluation of vegetable oil conversion to methyl esters of fatty acids has been developed. These methyl esters, prepared by the transesterification of vegetable oil with methanol, are used as alternative fuel for diesel engines. A method of gas-liquid chromatography (GLC) on packed columns is used to determine the conversion of acyls bound in acylglycerols to methyl esters. This procedure is based on comparison of the peak areas of methyl esters in fuel samples before and after reaction with an effective transesterification reagent, which will transform unreacted acylglycerols to methyl esters. A correlation between the bound glycerol content, determined by the thin-layer chromatography/flame-ionization detector method, and the acyl conversion, determined by GLC, is given. In acyl conversions to methyl esters over 96.0%, the bound glycerol content is less than 0.25% by weight.     

Solvent extraction of ethanol from aqueous solutions using biobased oils, alcohols, and esters

Distribution coefficients and separation factors were determined for the partitioning of ethanol and water from aqueous mixtures into several vegetable oils and their fatty alcohol and fatty ester derivatives. Castor oil, ricinoleyl alcohol, and methyl ricinoleate all show higher ethanol distribution coefficients, and similar or reduced separation factors, relative to other oils and derivatives studied here or reported by others. Of particular interest, ricinoleyl alcohol has an ethanol distribution coefficient 50% higher than that of oleyl alcohol, a commonly studied solvent for ethanol extraction from fermentation broths.     

从废弃油脂生物柴油中分离不饱和脂肪酸甲酯

以废弃油脂制生物柴油为原料,以95%醇为溶剂,采用尿素包合法提取不饱和脂肪酸甲酯,为生物柴油联产具有高附加值化工产品打下基础.重点考察了尿素用量、溶剂用量、包合时间和包合温度对不饱和脂肪酸甲酯分离效果的影响.结果表明,尿素包合法从生物柴油中分离不饱和脂肪酸甲酯的适宜工艺条件为:尿素,生物柴油质量比为1.4～1.7,溶剂/生物柴油质量比为4.6～6.0,包合温度为10℃,包合时间为18 h.在适宜条件下,不饱和脂肪酸甲酯含量可达93.5%,收率可达55.8%.