共查询到20条相似文献,搜索用时 140 毫秒
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山梨(糖)醇的合成及应用 总被引:2,自引:0,他引:2
简要介绍了山梨醇的性质和合成方法,同时介绍了以Ru-Pd/ACF为固定床催化剂合成山梨醇的实验方法,并简述了山梨醇在食品、医药、化妆品、纺织品等行业的应用。 相似文献
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TSA催化合成1,3:1,4———:二亚苄基山梨醇的研究 总被引:1,自引:0,他引:1
研究了利用多种催化剂在不同条件下合成1,3:2,4-二亚苄基山梨醇。结果表明:采用TSA为催化剂,当山梨醇:苯甲醛=1:2.4(摩尔比),催化剂、甲醇、环己烷用量分别为反应基础物的4.0%、247%、584%(重量百分含量),反应温度75℃,反应时间5hr时,产率可高达95.6%。 相似文献
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介绍了采用高聚物法以山梨醇为多元醇制备醇酸树脂的合成过程,并对结果进行了讨论。山梨醇改性醇酸树脂制漆具有优良的性能。 相似文献
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分析和计算山梨醇与3,4-二甲基苯甲醛合成山梨醇缩醛反应的热力学对于开发该反应的催化剂和反应工艺具有重要意义。首次利用Benson法计算了山梨醇一缩-3,4二-甲基苯甲醛(MDMBS)、山梨醇二缩3,4-二甲基苯甲醛(DDMBS)和山梨醇三缩3,4-二甲基苯甲醛(TDMBS)的热力学参数,建立了MDMBS,DDMBS和TDMBS的热容与温度的关系方程。在此基础上,利用Kirchhoff方程,分别建立了山梨醇与3,4-二甲基苯甲醛缩合为MDMBS、DDMBS和TDMBS 3个反应的焓变与温度的方程。计算表明在300~1000 K温度范围内,山梨醇与3,4-二甲基苯甲醛缩合生成MDMBS、DDMBS和TDMBS的3个反应均为放热反应。 相似文献
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依据山梨醇酐脂肪酸酯系列产品合成反应的共性,建立了该系列产品合成反应的反应参数与质量参数的参数方程,并应用于山梨醇酐单硬脂酸酯的合成,取得了预期的结果。参数方程即数学模型圆满地解释了该系列产品生产中的种种规律,也为优化工艺条件、保证合格率为100%、简化检测工作提供了依据。重要的是,数学模型为间歇式反应实现自动控制及采用连续生产工艺开辟了道路。 相似文献
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酸催化合成烷基苄叉山梨醇二缩醛的研究 总被引:1,自引:0,他引:1
以烷基苯磺酸为催化剂,对原料山梨醇和烷基苯甲醛的非均相缩醛化反应进行了研究,考察了醛醇物质的量比,催化剂用量,疏水性有机溶剂用量以及搅拌速度对产品烷基苄叉山梨醇二缩醛(简称DRBS)收率的影响,找出了合成DRBS的合适条件,并对DRBS的物化性能进行了测试,实测值与文献值一致。 相似文献
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通过对目前我国某些企业甲醇中乙醇含量分析方法的调查和分析,发现其准确度偏差较大,利用光谱分析进行了对比实验研究,采取了几项改进措施,从而大大地提高了甲醇中乙醇含量分析方法的准确度,使企业可在生产中有效地控制甲醇中乙醇的含量。 相似文献
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This work investigated the impacts of the initial pH and salt of the dextrin solution on fractionating dextrin by gradient alcohol precipitation, represented by gradient ethanol precipitation. Data suggested that this method was applicable in acidic, neutral, and alkaline environment, and the best fractionation effect was achieved at neutrality. In addition, KCl was co-precipitated with dextrin and resulted in earlier precipitation of some dextrin than in the KCl-free solution, which indicated that salt negatively affected fractionation. Furthermore, the effect of salt was positively correlated to its concentration. 相似文献
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In situ esterifications of high-acidity rice bran oil with methanol and ethanol and with sulfuric acid as catalyst were investigated.
In the esterification with methanol, all free fatty acids (FFA) dissolved in methanol were interesterified within 15 min,
and it was possible to obtain nearly pure methyl esters. The amount of methyl esters obtained from a given rice bran was dependent
on the FFA content of the rice bran oil. In the esterification with ethanol, it was not possible to obtain pure esters as
in methanol esterification, because the solubilities of oil components in ethanol were much higher than those in methanol. 相似文献
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Meitang Jin Zhao Xu Ying Bao Long Li Liping Wang Haijiao Lu Chuang Xie Hongxun Hao 《中国化学工程学报》2019,27(2):362-368
Omeprazole sodium(OMS), a typical non-hydrogen bond donors API, is only available in solvates so far, including monohydrate, ethanol solvate and methanol solvate. The methanol solvate was found for the first time. Solvate transformation thermodynamics of OMS was studied in this paper. First, the ternary phase diagrams forming two solvates for OMS in binary solvent mixtures including methanol + water, ethanol + water, and methanol+ ethanol were measured at temperature ranging of T =(278.15 to 313.15) K under atmospheric pressure. Further, the standard equilibrium constants of the solvate transformation reactions were evaluated according to the chemical reaction isothermal equation. The standard molar Gibbs free energy, the standard molar enthalpy, and the standard molar entropy of solvate transformation reactions were then calculated based on van't Hoff equation. Moreover, the thermodynamic stability of the OMS solvate was analyzed based on phase diagram. The results are of great importance to develop a crystallization process for manufacturing OMS solvate, and could be helpful to other solvate transformation research. 相似文献
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Iodine which is generally a non-conductor in non-polar solvents, conducts electricity in methanol, ethanol and water. The majority of the charge carriers in the solutions of charge-transfer complexes of methanol—iodine and ethanol—iodine are anion constituents (t25°C? are 0.739, 0.728 for 0.1 N solution of iodine in methanol and ethanol respectively) and for water—iodine it is cation constituents (t25°C+ is 0.905 for 0.0024 N iodine). The transport number of anion decreases with the increase in temperature whereas it increases with the increase in concentration at 25°C. 相似文献
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通过研究木质素分别在超临界甲醇和乙醇溶剂中的液化过程,分析反应温度(260~340℃)及反应时间(0~120min)对木质素在两种溶剂中的转化率、生物油收率及其组分差异的影响。实验表明,木质素在超临界乙醇中的转化率及产物收率均高于甲醇。当反应温度340℃,反应时间60min,木质素在超临界乙醇中的转化率和生物油收率比在甲醇中分别提高了16.23%和11.54%,残渣收率降低了16.23%。通过GC-MS和FTIR对生物油和残渣分析,发现生物油组分中芳香族化合物相对含量较高,在甲醇和乙醇溶剂中分别达到66.13%和58.84%;随着反应时间的延长,甲醇溶剂中残渣的醚键官能团逐渐增强,而在乙醇溶剂中则先增强后减弱。分析认为在木质素降解过程中,超临界乙醇和甲醇均可产生氢自由基作为供氢体,攻击木质素及其大分子片段中的官能团,同时使液化产物中的活性片段减活,减弱重聚合反应,从而更利于芳烃产物的生成。而甲醇在液化过程中容易与木质素断键产生的苯酚中间体发生脱氢缩合反应,通过醚键聚合产生长链芳香族化合物,形成残渣,降低生物油收率。 相似文献