Preferential degradation of noncholine phosphatides in soybean lecithin by thermalization

Purified soybean lecithin and the gum derived from soybean oil processing were heated separately in bulk at 125 to 200°C for 60 min, or at 175°C for 30, 60, 90 and 120 min, and the products were analyzed by thin-layer chromatography and high-performance liquid chromatography. It was found that the noncholine phosphatides are preferentially degraded relative to phosphatidylcholine, and that these phosphatides are broken down in the order phosphatidyl-ethanolamine (PE)>phosphatidylinositol (PI)>phosphatidic acid (PA) with increasing temperature. At 175°C, the heating time required to degrade the noncholine phosphatides was between 30 and 60 min. Diglycerides were the principal products of thermalization at 77% of the total material, indicating that the 3-phosphoester linkage is the most heat-labile portion of the noncholine phosphatide molecules. Cleavage of the fatty acids from positions 1 and 2 of the phosphatides was minimal, as indicated by the relatively low amount of free fatty acids (8% of the total) when the lecithin was heated at 180°C for 90 min. The appearance of brown discoloration, characteristic of heated lecithin, coincided mainly with the decomposition of PE.     

含聚合型乳化剂反相乳液体系的稳定性研究

以煤油为油相,丙烯酸钠水溶液为水相,自制的非离子聚合型乳化剂-Span80丙烯酸酯(Span80AA)、Span80和Twen80组成复合乳化剂,制备反相乳液。计算出Span80AA的HLB值,考察了乳化剂浓度、水相体积分数Φ及单体浓度对乳液类型及稳定性的影响。结果表明:HLB(Span80AA)=2.709;Span80AA、Span80和Twen80的最佳质量比为0.8∶0.3∶0.1。形成稳定的反相乳液理想条件是:复合乳化剂质量分数为6%~8%;Φ<57%;单体浓度为2.0~3.5 mol/L。     

油包水钻井液抗高温乳化剂的优选

提高乳化剂的抗温能力是目前抗高温油基钻井液发展的技术难题之一。通过对表面活性剂的优选和复配,优选出了一种适用于白油的抗高温油包水型乳化剂。通过电稳定性评价法、乳化率评价法、离心评价法、高温老化实验,系统考察了该乳化剂的性能及其乳状液的稳定性。结果表明:以乳化剂PF-MOMUL-HT为主乳化剂,PF-MOCOAT-HT为辅乳化剂,选择3#白油为基础油,优选其他处理剂,可以构建出性能不错的抗高温油基钻井液。     

The effect of monoethylene glycol on the stability of water-in-oil emulsions

It is important from both a strategic and economic standpoint to study the mechanism of formation of water/oil emulsions, to predict their increase of viscosity with respect to that of the crude oil, and to obtain information about the stability vs separation of these substances (since their presence can impair oil processing and distribution). The objective of this work was to ascertain the influence of monoethylene glycol (MEG) on these parameters and its action mechanism. The addition of MEG in different proportions in the oil emulsions significantly changed the flow curve of the emulsion, passing from a quasi-Newtonian one to a shear thinning behaviour. Besides this, when MEG was present at low concentrations, the demulsification process was slow and an increase in concentration made the emulsions more stable than samples containing the same aqueous phase proportion. Under the conditions studied, the addition of MEG did not reduce the quantity of the aqueous phase separated compared to the emulsions free of MEG, but significantly delayed the demulsification process. Rheology provided important information regarding the phase separation process of the aqueous phase in oil phase emulsions, and dynamic testing suggested that the most relevant effect of the addition of MEG is an increase of the emulsion elasticity that can be correlated with the increase in the emulsion stability observed by bottle test and Turbiscan.     

A novel technique for preparing organophilic silica by water-in-oil microemulsions

Summary A novel technique to prepare ultramicro spherical silica particles containing vinyl groups on their surfaces is presented. This process is a combination of the sol-gel technique and the water-in-oil microemulsion technique in which hydrolysis and condensation of TEOS [Si(OEt)₄] and MPS (trimethoxysilylpropylmethacrylate) take place. Spherical silica particles with a size range from 20 to 70 nm were obtained and the surface concentrations of the double bonds per nm² were from 4 to 7.     

Studies on stability of rapeseed wet gum as a source of pharmaceutical lecithin

Lecithin wet gum with high water content is less stable during storage than dry lecithin. Deoiling and dehydrating the fresh gum can result in a purified lecithin of high quality. The stability of rapeseed wet gum obtained from double-zero rapeseed varieties was determined at various temperatures. The effect of storage time on volatile substances, acetone insolubles, neutral lipids and acid, iodine, and peroxide values were investigated. The rapeseed wet gum stored a little above 20°C is stable for up to ten days, although in the frozen state (−20°C) no changes in general composition, acid, iodine, and peroxide values were observed during 24 mon of storage.     

水性环氧乳化剂的研制

采用E-51环氧树脂和不同分子质量聚醚多元醇反应合成了反应性水性环氧树脂乳化剂,并用相反转技术制备了一系列水性环氧树脂乳液,考查了催化剂、聚醚多元醇的分子质量以及环氧基／羟基比等对环氧树脂乳液的离心、冻融、稀释稳定性的影响。结果表明,采用三氟化硼胺络合物为催化剂,聚醚多元醇相对分子质量为3000～6000,n环氧基／羟基为2：1,于120℃反应合成的乳化剂具有较好的乳化效果。乳化剂用量为20％时,在60℃所配制的乳液稳定性最好,乳液粒径约0．38μm,室温放置6个月乳液不分层。     

一种脂多糖类乳化剂对稠油的乳化降黏研究

黄原胶和HBS-1都是微生物代谢产生的胞外聚合物。为了有效的降低NB 35-2稠油的黏度,进行了这两种生物聚合物及其与α-烯烃磺酸盐(AOS)复配对稠油的乳化对比实验。实验结果表明,当w(黄原胶)≥0.20%或复配体系中w(黄原胶)≥0.10%(w(AOS)=0.06%)时,形成的乳状液的稳定性好。随HBS-1质量分数增加,乳状液的稳定性提高,黏度下降;当HBS-1与AOS复配后,复配体系(w(HBS-1)=0.05%和w(AOS)=0.06%)形成的乳状液稳定性进一步提高,黏度也明显下降。此复配体系有利于NB 35-2稠油的乳化开采和运输。     

Particle nucleation mechanism for the emulsion polymerization of styrene with a novel polyester emulsifier

The particle nucleation mechanism in emulsion polymerization of styrene with a novel polyester emulsifier, 5‐sulfoisophthalic acid dimethyl ester sodium salt‐modified tetracarboxylic acid‐terminated polyester (SMTAPE), was investigated. The consumption of SMTAPE micelles was monitored by the measurement of surface tension during the emulsion polymerization. Kinetic studies and emulsifier consumption clearly showed that a continuous nucleation mechanism without Smith–Ewart interval II was characteristic of this system. It was attributed to the high concentration of SMTAPE emulsifier in the polymerization, which led to a large surface area and a vast number of micelles around 10 nm in size that served as the major locus of particle nucleation. A broad particle size distribution was observed throughout the reaction, and the nucleation period lasted well into the reaction until the disappearance of the micelles or the disappearance of monomer droplets. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1061–1070, 2001     

乳化体系对氟硅改性丙烯酸酯乳液性能的影响

采用不同的乳化体系来制备氟硅改性丙烯酸酯乳液,主要探讨了乳化体系对预乳化液稳定性、聚合稳定性、储存稳定性、转化率、粒径大小与分布以及吸水率的影响。结果表明,在所采用的乳化体系中,由聚氧乙烯-4-酚基醚硫酸铵盐(CO436)与1-丙烯基-α-羟基烷基磺酸钠(COPS-1)组成的复合乳液体系,可制得转化率高达98.85%的稳定乳液,乳液粒径呈单分散分布,乳胶膜的吸水率只有4.31%。     

Effect of lipid type on water‐in‐oil‐emulsions stabilized by phosphatidylcholine‐depleted lecithin and polyglycerol polyricinoleate

Water‐in‐oil (W/O, 30:70) emulsions were prepared with phosphatidylcholine‐depleted lecithin [PC/(PI,PE) = 0.16] or polyglycerol polyricinoleate (PGPR) as emulsifying agents by means of pressure homogenization. The effect of lipid type (medium‐chain triacylglycerols, sunflower, olive, butter oil, or MCT‐oil/vegetable fat blends) was investigated in relation to particle size distribution, coalescence stability and the sedimentation of the water droplets. A significant correlation (p <0.05) was observed between the interfacial pressure caused by the addition of lecithin to the pure lipids and the specific surface area of the emulsion droplets (r_s = 0.700), and between the viscosity of the lipids used as the continuous phase (reflecting the fatty acid composition) and the specific surface area of the emulsion droplets (r_s = 0.8459) on the other hand. Blends of vegetable fat and MCT‐oil led to reduced coalescence stability due to the attachment of fat crystals to the emulsion droplets. Lecithin‐stabilized W/O emulsions showed significantly higher viscosities compared to those stabilized with PGPR. It was possible to adjust the rheological properties of lecithin‐stabilized emulsions by varying the lipid phase.     

聚氨酯预聚体——可聚合乳化剂用于MMA乳液聚合动力学及聚合稳定性研究

将合成的聚氨酯预聚体可聚合乳化剂（APUA）用于甲基丙烯酸甲酯（MMA）乳液聚合体系中，研究了不同引发剂体系和乳化剂对聚合体系的聚合稳定性和动力学影响，并与SDS乳化剂进行了对照。结果显示，用油溶性引发剂（AIBN）和水溶性引发剂（K2S2O8）都能引发该体系的聚合反应，而且聚合速率和转化率都相当高。用AIBN作引发剂时，APUA和SDS两种乳化所对应的动力学曲线不同，但APUA比SDS的聚合速率大得多，其分别类似于微乳液聚合（miniemulsion)和微悬浮聚合（microsuspention)，且聚合过程中会产生一定的凝胶。当乳化剂APUA用量适合时，凝胶量极少，聚合体系是稳定的；而当用K2S2O8作引发剂时，两乳化剂对应动力学曲线相似，聚合过程不产生凝胶。但当引发剂用量较大并以APUA作乳化剂时，在聚合过程中会出现全部粒子突然粗化现象，而以SDS作乳化剂没有出现这一现象。     

Effect of molecular weight on preparation of nanoparticles by particle dissolution method from submicron-sized ionized styrene–methacrylic acid copolymer particles in nonionic emulsifier solution

Styrene–methacrylic acid copolymer [P(S-MAA)] (92/8, molar ratio) nanoparticles were prepared by a dissolution of submicron-sized P(S-MAA) particles with various molecular weights in a polyoxyethylene nonylphenylether nonionic emulsifier aqueous solution at pH 13.0 and above 90°C. The latter particles were produced by emulsion copolymerization in the presence of various concentrations of n-octyl mercaptan. The effect of molecular weight on the dissolution behavior was examined at various conditions and using various kinds of the nonionic emulsifier. It was clarified that a decrease in the molecular weight led to the production of the nanoparticles at mild treatment conditions. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1461–1464, 1997     

Influence of concentration and temperature on the flow behavior of oil-in-water emulsions stabilized by sucrose palmitate

To study the influence that concentration and temperature exert on the viscous behavior of emulsions stabilized by a sucrose ester (SE) of high hydrophilic-lipophilic balance (HLB), flow curves and droplet size distributions were determined. Flow curves of presheared emulsions always exhibited a shear-thinning behavior at intermediate shear rates, a tendency to a limiting viscosity at high shear rates, and a metastable region at low rates. This behavior can be fitted to a Carreau model. Both SE and oil concentrations increase emulsion viscosity as a result of a more structured system with a lower droplet size and polydispersity. An increase in temperature usually leads to a decrease in emulsion viscosity. However, at high oil concentration, coalescence and phase separation take place at low temperature. On the other hand, at high temperature, droplet bursting due to shear forces, leading to an increase in viscosity, may result. Despite the strong structural breakdown caused by steady shear, master flow curves may be obtained by using superposition methods.     

一种渣油乳化燃料油的制备研究

根据表面活性剂知识,采用HLB值法筛选和复配乳化剂.观察乳化燃料油离心分离后出水情况,显微镜观察其内部水颗粒状况,分析乳化燃料油的稳定性,以稳定性为依据,选择复配乳化剂及其HLB值,并确定合理的乳化加工工艺;对影响乳化燃料油的因素进行分析.     

High-performance poly(butylene oxide)/poly (ethylene oxide) block copolymer surfactants for the preparation of water-in-oil high internal phase emulsions

High-performance surfactants have been developed for the preparation of water-in-oil high internal phase emulsions (HIPE), particularly for the preparation of polymerized HIPE foams. High-efficiency surfactants with poly(butylene oxide)/poly(ethylene oxide) (BO/EO) block copolymer backbones have been developed that can stabilize an HIPE through polymerization at concentrations as low as 0.006 wt% based on total emulsion weight. Polymerizable versions have been developed that bind into the polymeric foam backbone. BO/EO block copolymer surfactants also allow preparation of polymerized HIPE foams without salt in the aqueous phase. HIPE with the BO/EO surfactants have been prepared at room temperature and polymerized at temperatures exceeding 90°C. By minimizing the required amount of surfactant, allowing the surfactant to react during HIPE polymerizations, eliminating the need for salt, and stabilizing over a broad range of temperatures, BO/EO block copolymer surfactants have demonstrated their place as high-performance HIPE surfactants.     

非平衡级法气体混合物吸收-水合双塔分离单元的模拟计算

水合物技术应用于低沸点气体混合物分离的优势在于其可在0℃左右操作,因此可极大地降低制冷所消耗的能量。由于此分离方法尚处在理论研究阶段,还不能实现工业化,因此对操作流程模拟计算的研究很有必要。采用非平衡级法(速率法)对水合塔-吸收塔串联操作流程进行了模拟计算,其中涉及水合物生成动力学模型、水合物分解动力学模型以及混合气体在乳液相的吸收传质动力学模型。探讨了两个串联分离塔操作参数,如温度、压力等,对分离效率的影响,所得结果对水合物技术分离低沸点气体混合物流程的设计有重要意义,同时也可为以后的工业化奠定一定的理论基础。     

Extraction of alcohol using emulsion liquid membrane consisting of paraffin oil as an organic phase and lecithin as a surfactant

BACKGROUND: This paper reports on the use of a liquid emulsion membrane involving paraffin light oil as membrane phase and lecithin as surfactant for the extraction of alcohol from anthocyanin extract and simulated pineapple wine. RESULTS: The extraction of alcohol was found to depend on the many factors such as surfactant concentration, contact time, stirring speed, stirring time, and ratio of membrane emulsion to feed volume. Results showed that optimum conditions for maximum alcohol extraction (25%) were lecithin concentration 3%, contact time 20 min, stirring speed 250 rpm and ratio of membrane emulsion to feed volume 1:2. Multistage extraction using this liquid emulsion membrane was found to completely remove alcohol from anthocyanin extract and from simulated pineapple wine in seven stages and five stages, respectively. CONCLUSION: This liquid emulsion membrane was found to be a useful method for the extraction of alcohol from aqueous feed. Copyright © 2009 Society of Chemical Industry     

The fuel properties of three-phase emulsions as an alternative fuel for diesel engines

Diesel engines are employed as the major propulsion power for in-land and marine transportation vehicles primarily because of their rigid structure, low breakdown rate, high thermal efficiency and high fuel economy. It is expected that diesel engines will be widely used in the foreseeable future. However, the pollutants emitted from diesel engines (in particular nitrogen oxides and particulate matter) are detrimental to the health of living beings and ecological environment have been recognized as the major air pollution source in metropolitan areas and have thus attracted much research interest. Although diesel oil emulsion has been considered as a possible approach to reduce diesel engine pollutants, previous relevant applications were restricted to two-phase emulsions. Three-phase emulsions such as oil-in-water-in-oil briefly denoted as O/W/O emulsions and water-in-oil-in-water, denoted as W/O/W, have not been used as an alternative fuel for any combustion equipment. Studies on the properties of three-phase emulsion as fuel have not been found in the literatures. The emulsification properties of an O/W/O three-phase diesel fuel emulsion were investigated in this experimental study. The results show that the mean drop size of the O/W/O emulsion was reduced significantly with increasing homogenizing machine revolution speed. An increase in inner phase proportion of the O/W/O emulsion resulted in increasing the emulsion viscosity. The viscosity of O/W/O emulsion is greater than that for water-in-oil (denoted briefly as W/O emulsion) for the same water content. More stable emulsion turbidity appeared for three-phase O/W/O diesel emulsions added with emulsifier with HLB values ranging from 6 to 8. In addition, three-phase O/W/O emulsions with greater water content will form a larger number of liquid droplets, leading to a faster formation rate and greater emulsion turbidity at the beginning but a faster descending rate of emulsion turbidity afterwards. The potential for using O/W/O emulsions as an alternative fuel for diesel engines was also evaluated.     

Healthier lipid combination oil‐in‐water emulsions prepared with various protein systems: an approach for development of functional meat products

Five protein‐stabilized oil‐in‐water emulsions were prepared using sodium caseinate (O/SC), soy protein isolate (O/SPI), sodium caseinate and microbial transglutaminase (O/SC + MTG), sodium caseinate, microbial transglutaminase and meat slurry (O/SC + MTG + MS) and SPI, sodium caseinate and microbial transglutaminase (O/IPS + SC + MTG); their composition (proximate analysis and fatty acid profile) and physicochemical characteristics were examined. The lipid phase was a combination of healthy fatty acids from olive, linseed and fish oils, containing low proportions (15%) of saturated fatty acids (SFA) and high proportions of monounsaturated fatty acids (MUFA, 47%) and polyunsaturated fatty acids (PUFA, 36%), with a PUFA/SFA ratio >2, and a n‐6/n‐3 PUFA ratio of 0.4. All the oil‐in‐water emulsions showed high thermal and creamy stability. Results of penetration test and dynamic rheological properties showed la existencia de different types of oil‐in‐water emulsion structures according to stabilizing system of emulsion. Those structures ranged from concentrate solution‐like (stabilized only with SC) (gel strength 0.06 mJ) to gel‐like (samples containing MTG) behaviours (gel strength ranged between 3.4 and 6.2 mJ). Morphological differences in the organization of the network structure were observed (by scanning electron microscopy) as functions of the protein system used to stabilize the oil‐in‐water emulsions.