复合酸催化合成乙二醇单硬脂酸酯

以浓硫酸、对氨基苯磺酸作复合催化剂,采用正交实验对乙二醇单硬脂酸酯的合成条件进行了研究,并与ｓｐａｎ－６０等表面活性剂复配,制备消泡剂。     

改性超支化聚甘油醚的制备及应用

以甘油和缩水甘油为原料,甲醇钠为催化剂,采用阴离子开环聚合法合成第三代超支化聚甘油醚(HBPG),并对产物用油酸进行不同程度的端基改性,制备HBPG-X系列产品。通过FTIR和~1HNMR对HBPG及HBPG-X的结构进行表征,并将HBPG-X系列产品应用于绵羊皮服装革加脂实验,同时与市售加脂剂SK-70作对比。结果表明:HBPG-X系列产品可使成革柔软,并能提高成革的抗张强度和撕裂强度,对成革的透水汽性影响较小。其中,HBPG-1产品加脂效果最好,成革柔软度与SK-70相当。     

改性松香基非离子表面活性剂的合成及性能

以松香和聚甘油为原料,合成了一种松香基非离子表面活性剂,得到不同甘油聚合度的产物。得到的松香基非离子表面活性剂的表面物化性能为:表面张力44 2～49 6mN/m;临界胶束浓度8 0×10-4～25 6×10-4mol/L;钙皂分散指数13 5%～21 5%;界面张力11 7～18 9mN/m;乳化力44～85s;泡沫性能6～46mm;润湿力87～121s。并对甘油聚合度和产物表面性能的关系进行了考察。     

酯交换法合成聚甘油丙烯酸酯

以聚甘油、丙烯酸甲酯为原料，利用酯交换法，以硫酸为催化剂，对苯二酚为阻聚剂，无溶剂，在共沸温度下，合成了一种水溶性聚甘油丙烯酸酯破乳剂。考察了催化剂用量、阻聚剂用量、反应时间、聚甘油中羟基与丙烯酸甲酯之摩尔比、不同聚合度聚甘油合成的聚甘油丙烯酸酯对原油乳状液脱水率的影响。实验表明，考察的影响条件均存在最佳值，即在催化剂用量占反应物总量的2％（w），阻聚剂用量占丙烯酸用量的2％（w），反应时间16h，聚甘油中羟基与丙烯酸甲酯之摩尔比为2．6：1，聚甘油聚合度为6．3，在破乳剂用量为300mg／L时，破乳脱水率达69％。     

Effect of polyglycerol esters of fatty acids on physicochemical properties and stability of β‐carotene nanodispersions prepared by emulsification/evaporation method

The effects of six different polyglycerol esters of fatty acids (PGEs) as nonionic emulsifiers on the physicochemical properties and stability of β‐carotene nanoparticles in oil‐in‐water dispersions produced by an emulsification/evaporation technique were examined. The β‐carotene particle size was measured by a laser diffraction technique, and the stability and retention of β‐carotene during various preparation steps and storage were determined by HPLC. In the prepared nanodispersions the β‐carotene particle size decreased with increasing degree of glycerol polymerisation and decreasing carbon number of the fatty acid group in the PGE. The particle size of β‐carotene in nanodispersions containing polyglycerol monooleate was generally larger than that in the presence of polyglycerol monolaurate. During storage at 4 °C, although the β‐carotene content in the nanodispersions showed a significant ( P < 0.05) decrease with increasing storage period, the size distribution of β‐carotene was almost unchanged in all prepared nanodispersions. In general, the mean diameter of β‐carotene nanoparticles ranged from 85 to 132 nm. In the light of their ability to physically stabilise β‐carotene particle formation, it is suggested that PGEs with a high degree of glycerol polymerisation may be useful in the preparation of β‐carotene nanodispersions. The best stabilisation was obtained using 10 g kg^?1 decaglycerol monolaurate. Copyright © 2004 Society of Chemical Industry     

单硬脂酸丙二醇酯及其应用

高纯度单硬脂酸丙二醇酯多作为乳化剂在食品工业中广泛应用，阐述了单硬脂酸丙二醇酯的性质、生产、质量及其在食品中的应用状况。     

KF/ZrO_2/Fe_3O_4磁性固体碱催化合成聚甘油的研究

在复合磁性载体ZrO_2/Fe_3O_4上负载碱源KF,制备出KF/ZrO_2/Fe_3O_4磁性固体碱催化剂,通过扫描透射电镜、比表面测试、碱强度、碱量测定等方法对催化剂的形貌结构与碱性进行表征,并将其应用于聚甘油的催化合成中,评价其催化性能。结果显示,该磁性固体碱催化剂表面负载有一定量的KF碱性活性中心,碱强度pH在11.1～15.0之间,总碱量为0.2mmol/g,为固体强碱类催化剂。在聚甘油合成中,反应条件温和,产品聚合度适中,色泽较浅,产物与催化剂易分离,表现出明显的催化活性,具有较高的应用价值与经济价值。     

Emulsifiers affect the texture of pastes made from fermented and non-fermented cassava flours†

The effects of glycerol monostearate (GMS) and sodium steroyl lactylate (SSL) on the rheological properties of native, naturally fermented (NF) and mixed culture fermented (MCF) cassava flour pastes were measured using instrumental texture profile analysis (TPA) and by finger cohesiveness (difficulty in separation). Fermentation reduced the TPA parameters, hardness, cohesiveness and gumminess, but not springiness/elasticity. These were reduced further when either GMS or SSL were incorporated into the pastes. Pastes made from native and naturally fermented flours were scored by a Cameroonian sensory panel as difficult to separate, whereas scores for native and fermented flour pastes treated with 1% or more of GMS or SSL were easy to separate. Increased internal stability of the cassava flour starch granules was suggested as the cause of the effects.     

Continuous Application of Polyglycerol‐Supported Salen in a Membrane Reactor: Asymmetric Epoxidation of 6‐Cyano‐2,2‐dimethylchromene

In the current work, suitability of hyperbranched polyglycerol as a high loading catalyst support is demonstrated. A polyglycerol‐supported manganese‐salen complex (chemzyme) is applied as a homogeneous catalyst in the epoxidation of 6‐cyano‐2,2‐dimethylchromene. The recyclability of the corresponding catalyst was investigated in repetitive batch experiments as well as a continuous operation of the reaction in an ultrafiltration membrane reactor. An enhanced stability of the catalyst in repetitive batches was observed as a result of immobilization whereby the total turnover number increased from 23 in a single batch to 80 in four repetitive batches. To enable continuous operation, a continuously operated, stirred tanked reactor (CSTR) was equipped with an ultrafiltration membrane (MPF‐50) and a retention of 98% was determined. The continuous chemzyme membrane reactor was operated over the course of 20 residence times. After approximately 12 residence times, the steady state was reached yielding 70% conversion as well as an enantiomeric excess up to 92%. A space‐time yield (sty) of 458 g L ⁻¹ d⁻¹ and a turnover frequency (TOF_reaction) of up to 18 h⁻¹ was reached in the steady state. It was determined that the total turnover number (TTN) was enhanced by a factor of 10 from 24 (batch) up to 240 for 20 residence times in CSTR operation.