共查询到20条相似文献,搜索用时 109 毫秒
1.
无溶剂法合成蔗糖硬脂酸酯的工艺研究 总被引:7,自引:0,他引:7
以乙醇代替有毒的甲醇与硬脂酸在酸催化下进行反应制出了硬脂酸乙酯。以硬脂酸乙酯与蔗糖为原料在催化剂和乳化剂的作用下,进行酯交换反应合成出蔗糖硬脂酸酯。详细考察了该合成反应过程中乳化剂、催化剂用量,反应温度,原料配比,反应时间等因素对蔗糖硬脂酸酯产率的影响,得出了较佳合成工艺条件,即硬脂酸乙酯:蔗糖摩尔比为2.15:1,乳化剂与蔗糖质量比为0.1:1,催化剂与反应物料质量比为0.14:1,反应温度-120℃,压力-4.35kPa,反应时间-3.5h。以蔗糖计,蔗糖酯产率约75.2%。此外,还把蔗糖硬脂酸酯制成易挥发衍生物,建立了分析其组成的气相色谱方法。 相似文献
2.
3.
4.
5.
本文以硬脂酸和无水乙醇为原料、浓流酸为催化剂,进行硬脂酸乙酯的合成研究。采用正交实验考察了醇酸的量比、反应时间及反应温度对合成硬脂酸乙酯的影响,实验结果表明:醇酸的量比为12.7、反应时间为6h及反应温度为80℃是最佳反应条件。 相似文献
6.
通过测定蔗糖硬脂酸单酯、双酯溶液和单酯双酯混合物溶液的表面张力,运用热力学方法研究计算蔗糖硬脂酸酯混合物体系的体相表面相分离系数,结果表明在实验条件下,蔗糖硬脂酸单酯和双酯的平均分离系数为13.24。 相似文献
7.
8.
为了克服蔗糖酯的水溶性差和有盐与酸性条件下乳化性能差的缺陷,该文采用马来酸酐对硬脂酸蔗糖酯进行改性,在硬脂酸蔗糖酯分子中引入羧基,设计合成了阴离子-非离子两性表面活性剂马来酸硬脂酸蔗糖酯(Sucrose stearate-maleate,MSS)。通过1HNMR和ESI-MS确证了产品结构。与硬脂酸蔗糖酯相比,MSS具有优良的水溶性。在酸性和有盐条件下,MSS的乳化性能较硬脂酸蔗糖酯得到了显著提高。同时发现,MSS还具有优异的硬水稳定性(5级)。 相似文献
9.
以蔗糖和原乙酸三乙酯为原料,对甲苯磺酸为催化剂,酯化合成蔗糖-4,6-环酯,水解生成蔗糖-4-乙酯和蔗糖-6-乙酯,在叔丁胺作用下蔗糖-4-乙酯发生酰基迁移,转化为蔗糖-6-乙酯。考察了物料比、反应温度、催化剂和水的用量对反应的影响。研究表明适宜的条件为:6.84 g蔗糖需要10 mL原乙酸三乙酯、50 mg对甲苯磺酸,0℃反应180 min,加3 mL水裂解反应90 min,再加1 mL叔丁胺,酰基迁移反应90 min。产品经二氯甲烷析晶纯化,纯度达到96.5%。用ESI、1HNMR进行了表征。 相似文献
10.
相转移催化合成蔗糖硬脂酸酯 总被引:1,自引:0,他引:1
采用相转移催化的基本原理和方法合成蔗糖硬脂酸酯,考察了反应时间、反应温度、原料的不同配比和催化剂用量对蔗糖硬脂酸酯产率的影响,得出反应时间为3 h,反应温度为95-100℃、硬脂酸甲酯与蔗糖的摩尔比为1:2.5,硬脂酸甲酯与PTC之比为1:0.07时为最佳配比。 相似文献
11.
Sugar esters of fatty acids are bio-based surfactants that were synthesized by transesterification of table sugar (sucrose) with stearic acid methyl ester (SAME) in high yield and purity using an optimized microwave-assisted method. The maximum surfactant product yield of 88.2% was obtained by combining reactants with potassium methoxide and irradiating the mixture with microwaves to achieve an ideal reaction temperature of 132 °C over 21 min. The synthetic procedure described herein minimized undesirable sugar pyrolysis as evidenced by retention of white color characteristic of a pure bio-based surfactant product. The experiment implemented Box–Behnken design for response surface methodology to refine reaction parameters for optimal product yield. The following parameters were augmented: the irradiation time, the mole ratio of catalyst to sucrose, and temperature. 相似文献
12.
以柠檬酸、季戊四醇、硬脂酸为原料,采用直接酯化的两步反应合成了柠檬酸硬脂酸季戊四醇酯蜡,并对反应条件进行了优化。固定季戊四醇为0.1 mol的最佳条件为:第一步反应温度为200℃,时间1 h,硬脂酸用量28 g,催化剂为总质量的0.4%;第二步柠檬酸用量为10 g,反应温度150℃,反应时间3 h。最终产物为蜡状物质,酸值为2.2 mgKOH/g,针入度为0.1 mm,滴熔点为70℃。 相似文献
13.
采用离子交换法制备了硬脂酸柱撑类水滑石,采用红外光谱分析对其结构进行了表征。通过HAAKE流变仪、颜色测定仪研究了硬脂酸柱撑类水滑石与钙锌热稳定剂并用时的热稳定性,重点考察了水滑石的结构对PVC稳定性能的影响。结果表明硬脂酸柱撑类水滑石与钙皂/锌皂复配显著改善了PVC热老化过程中的初期着色性。 相似文献
14.
15.
16.
Siswati Lestari Päivi Mäki-Arvela Irina Simakova Jorge Beltramini G. Q. Max Lu Dmitry Yu. Murzin 《Catalysis Letters》2009,130(1-2):48-51
The deoxygenation experiments of different reactants, i.e., pure palmitic acid, stearic acid, and a technical grade stearic acid containing a mixture of 59% of palmitic and 40% of stearic acid were successfully performed over 4 wt% Pd/C mesoporous catalyst at 300 °C under 17 bar of 5% H2 in argon. The main product in catalytic deoxygenation of saturated fatty acids, C16 and C18, were aliphatic chain length hydrocarbons containing one less carbon than the corresponding acid. Additionally it was found that the deoxygenation rates of different reactant were independent on carbon chain length of its fatty acids. 相似文献
17.
Stearic acid adsorbed on alumina as a dense monomolecular layer was photochlorinated in the dry solid state. The results show that over 90% of the chlorination was on the ω and ω-1 positions and 8.5% on ω-2. No chlorination was detected on the other positions. This establishes the assumption that in a dense monomolecular layer only the terminal groups are exposed to chemical reaction. 相似文献
18.
19.
Hidero Unuma Kazutoshi Ito Toshitaka Ota Minoru Takahashi 《Journal of the American Ceramic Society》1996,79(9):2474-2476
The nucleation and growth of hydroxyapatite (HAp) crystals from solutions with and without Langmuir monolayers of stearic acid (SA) were investigated. The monolayers apparently enhanced the nucleation of HAp. Monolithic, filmlike polycrystalline HAp with preferred orientation of (00l) planes parallel to the monolayer interface was precipitated, while colloidal and powdery precipitation in the bulk solution was predominant in the absence of the monolayer. Geometrical similarity was found between the hexagonal packing conformation of the SA headgroups in the monolayers and the alignment of calcium ions in the (001) plane of HAp. It was suggested that HAp crystals nucleated and grew epitaxially on the monolayer interface. 相似文献
20.
在无溶剂条件下 ,以硬脂酸钠作为催化剂 ,利用二甘醇葡萄糖苷与硬脂酸直接酯化合成二甘醇葡萄糖苷硬脂酸酯 ,在反应温度为 180℃ ,反应时间 10h ,催化剂用量为反应物总质量11 1%的条件下 ,硬脂酸的转化率达 95 0 % 相似文献