含羧基有机蒙脱土/天然橡胶纳米复合材料的结构与性能

通过蒙脱土与酸化椰油酰胺基丙基甜菜碱(CAB)进行正离子交换,制备了含羧基的有机蒙脱土(OMMT),用OMMT与天然橡胶(NR)复合制得插层型纳米复合材料。对OMMT的结构进行了表征,研究了OMMT对NR/OMMT纳米复合材料结构与性能的影响。结果表明,酸化CAB溶液改性OMMT的层间距较蒙脱土改性者有较大幅度的增加;少量OMMT可改善NR的拉伸强度和扯断伸长率,同时维持较低的拉伸永久变形;OMMT对复合材料的硫化表现出促进作用,但其含量对复合材料的硫化特性影响不大。     

Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design,Development, and Kinetic Stability

Amphoteric amphiphilic compounds, due to their unique properties, may represent a group of safe and biocompatible surface-active agents for effective colloidal stabilization of nanoformulations. For this reason, the aim of this work was to develop and characterize the oil-in-water nanoemulsions based on two betaine-derived surfactants with high biodegradability, i.e., cocamidopropyl betaine and coco-betaine. In the first step, we investigated ternary phase diagrams of surfactant-oil-water systems containing different weight ratios of surfactant and oil, as the betaine-type surfactant entity (S), linoleic acid, or oleic acid as the oil phase (O), and the aqueous phase (W) using the titration-ultrasound approach. All the received nanoemulsion systems were then characterized upon droplets size (dynamic light scattering), surface charge (electrophoretic light scattering), and morphology (transmission electron as well as atomic force microscopy). Thermal and spinning tests revealed the most stable compositions, which were subjected to further kinetic stability analysis, including turbidimetric evaluation. Finally, the backscattering profiles revealed the most promising candidate with a size <200 nm for potential delivery of active agents in the future cosmetic, pharmaceutical, and biomedical applications.     

Amphoteric surfactants: processing, product composition and properties

Cocamidopropyl betaine (CAPB) has been the most important secondary surfactant for personal-cleansing products for a long time. Its excellent toxicological profile is an important reason for its increasing use in oral-care products. Recently it has gained interest for further applications such as household cleaners, dish-washing liquids, and industrial and technical products. Imidazoline-derived amphoterics such as sodium cocoampho-acetate (SCAA) or diacetate play a more minor role than CAPB. Owing to the low irritation potential of the pure surfactant and its good toxicological properties, ampho-acetates have mainly found applications in cosmetics. Their industrial applications have been relatively small. While CAPB has a well-defined chemical structure from a straightforward production process, most imidazoline-derived amphoterics exhibit a complex composition of compounds with different structures. This depends on the production parameters. Improved processing methods have recently led to the commercial availability of well-defined SCAA with low levels of by-products. Modern production processes and the composition of high-purity amphoterics are reviewed. Raw materials and by-products are described, together with their analytical methods. The cosmetic performance, cleansing and foaming power, rheological effects and mildness-enhancing properties of both CAPB and SCAA are compared. La cocamidopropyl-betaine (CAPB) est, depuis longtemps le tensio-actif secondaire le plus important pour les produits d'hygiene personnelle. L'excellent profil toxicologique de la CAPB est certainement une raison majeure de son usage croissant dans les produits de soin buccaux. La CAPB a suscite depuis peu un interet pour des applications supplementaires telles que les nettoyants menagers, les liquides vaisselle, les produits industriels et techniques. Les derives amphoteres de l'imidazoline tels que le cocoampho-acetate de sodium (SCAA) ou le diacetate occupent une place mineure comparee a la CAPB. En raison du faible potentiel irritant du tensio-actif pur et meme de bonne proprietes toxicologiques, les ampho-acetates trouvent principalement leurs applications dans les cosmetiqes. Leur role dans les applications industrielles est relativement limite. Alors que la CAPB a une structure chimique bien definie a partir d'un procede de production direct, la plupart des derives amphoteres d'imidazoline presentent une composition complexe de composes aux structures differentes. Ceci depend des parametres de production. Des procedes de production ameliores ont recemment conduit a une disponibilite commerciale de SCAA bien definis avec de faibles teneurs en produits secondaires. Les procedes modernes de production et la composition d'amphoteres de grande purete sont decrits. Les matieres premieres et les produits secondaires sont decrits ainsi que leurs methodes d'analyse. Le comportement cosmetique, le pouvoir nettoyant et moussant, les effets rheologiques et les proprietes adoucissantes sont compares, a la fois pour la CAPB et le SCAA.     

表面活性剂泡沫的影响因素研究

人们在使用洗涤产品时,都希望能够得到更多、更丰富的泡沫,所以泡沫的高低很大程度上可以作为衡量产品质量的主要指标。通过实验主要考察了在不同活性物浓度,不同水硬度条件和不同体系温度下,SLES、CAB和它们的复合物的泡沫性能,结果表明,SLES的泡沫性能受硬水影响不大,CAB的泡沫性能随浓度的变化而有所不同,SLES和CAB的复合物有更优秀的泡沫性能,表现出良好的协同增效性。     

离子色谱法测定椰油酰胺丙基甜菜碱中一氯乙酸和二氯乙酸

建立了离子色谱法测定椰油酰胺丙基甜菜碱中微量一氯乙酸(MCA)和二氯乙酸(DCA)的方法。采用3.2 mmol/L碳酸钠和1.0 mmol/L碳酸氢钠混合溶液作流动相,MCA和DCA检出限分别为0.011 mg/L和0.032 mg/L,线性相关系数分别为1.000 0和0.999 8,加标回收率分别为93.1%~101.8%和92.6%~99.1%,能满足工业分析要求。     

Safety to human skin of cocamidopropyl betaine: A mild surfactant for personal-care products

Cocamidopropyl betaine (CAPB) is a mild surfactant used in shampoos, conditioners, body washes, and other personal-care products. Several recently published case reports have suggested that CAPB may be a skin sensitizer. A 6-wk product-use study was conducted to determine whether subjects with previous positive patch tests to CAPB could use personal-care products (prototype hair shampoo, liquid handsoap, and body wash) with this surfactant without problems. Post-study patch testing suggested that amidoamine, a material used in the synthesis of CAPB and a contaminant of CAPB preparations, is a likely sensitizer. However, patch testing did not rule out the possibility that CAPB itself may be an allergen to a small number of presensitized individuals. It is recommended that CAPB with minimal levels of contamination be used for the formulation of personal-care products. Presented at INFORM '97 Session, 1997 American Oil Chemists' Society Annual Meeting & Expo, Seattle, Washington, May 12, 1997. Institution where work was done.     

椰油丙基酰胺甜菜碱/聚乙二醇水溶液的分相研究

Phase separation behavior of cocamidopropyl betaine/water/polyethylene glycol (PEG) system was studied. The effects of concentration and molecular weight of PEG on the phase separation behavior were investigated. Clouding occurred when the con-centration of PEG was large enough in the betaine aqueous solution, and the concentration of PEG at cloud point decreased with the increase of PEG molecular weight for a constant betaine concentration. The bottom phase was the PEG-rich phase, and the upper phase was the betaine-rich phase. The volumetric ratio of PEG-rich phase to betaine-rich phase, at the same difference between the PEG concentration and the one at the cloud point, &#61508;Ccp (0.1 g&#8226;ml－1), decreased as the PEG molecular weight increased and approached 1 for higher PEG molecular weight (about 20000), which was similar to the typical aqueous two-phase system. This volumetric ratio depended on the initial PEG concentration, but independent of PEG molecular weight. The concentration ratio of betaine to PEG in both phases depended on the &#61508;Ccp, independent of PEG molecular weight.