废油脂生物柴油副产甘油制备环氧氯丙烷的研究

为了延长生物柴油产业链,以废油脂生物柴油副产物粗甘油为原料,高值化利用生产衍生物环氧氯丙烷(ECH)。粗甘油原料被提纯成工业级甘油,经氯化反应和环化反应制备了环氧氯丙烷。以200 m L/min的氯化氢气体为氯化剂、己二酸为催化剂,在反应温度为105℃、己二酸质量分数为7. 5%的条件下,通过降温真空除水3次,制得二氯丙醇(DCP),氯化收率达93. 2%,甘油转化率达96. 7%。在氢氧化钠催化下二氯丙醇环化制得环氧氯丙烷。通过单因素实验得到环化反应的最佳工艺条件为:反应时间为30 min、氢氧化钠与二氯丙醇摩尔比为1. 2∶1、反应温度为90℃,在此条件下的环化收率为89. 5%。     

甘油合成二氯丙醇的研究进展

从反应机理、研究历史、最新进展和工业应用等方面,对甘油合成二氯丙醇的工艺进行了综述.早期研究以乙酸、丙酸、丁二酸、芳香羧酸和羧酸酯等催化剂,甘油与盐酸或氯化氢气体反应生成二氯丙醇产品混合物;利用苯、三氯苯、丁醚、氯丁烷等有机溶剂对反应产物萃取,可得高纯度二氯丙醇.最新研究开发了多种连续性生产工艺,在反应过程中及时蒸馏出生成的水分,促进反应平衡右移,提高转化率.采用高沸点的羧酸、羧酸酐、有机腈等催化剂,反应可在更高温度下进行,催化剂损耗较少;产物经减压蒸馏处理,二氯丙醇总收率达90%以上.中国有些厂家已经建设了甘油合成二氯丙醇装置并成功投产,国外也将利用该工艺生产环氧氯丙烷.     

甘油氯化法合成环氧氯丙烷

正该工艺包括2个步骤,首先是甘油与氯化氢在催化剂作用下反应生成二氯丙醇,再与液碱反应生成环氧氯丙烷。核心技术是氯化工艺和高效催化剂的选择。近年来甘油法的改进主要体现在反应器和催化剂两个方面。在固定床反应器中研究乙酸、草酸等对氯化反应的催化效果。结果表明,草酸和一氯乙酸作催化剂时,二氯丙醇的选择性很好,但甘油转化率低。用丙二酸、己二酸和葵二酸作催化剂时,甘油转化率有所提高,但二氯丙醇选择欠佳。当用冰醋酸作催化剂时,二氯丙醇选择性和甘油转化率都较高,分别为90.3%和85,5%。     

甘油氯化制备二氯丙醇过程中副产物处理的研究

甘油氯化制备二氯丙醇过程中会有副产物产生,通过分析二氯丙醇精馏釜余物的组成发现,高沸点物质主要是己二酸酯类,采用酯交换、水解、氢化还原3种方法进行处理,结果发现Pd/C催化加氢效果最好,己二酸的收率92.57%,二氯丙醇的收率78.53%。     

生物基甘油制备二氯丙醇工艺研究

利用生物柴油生产过程中副产的大量甘油,采用甘油氯化法生产二氯丙醇。分别以乙酸、丙酸、乙酸酐、乙二酸、丁二酸、三氯乙酸为催化剂进行生物基甘油与氯化氢的氯化反应,结果表明:以丙酸为催化剂时,二氯丙醇的收率最高。选择丙酸为催化剂,考察了反应温度、反应时间、HCl气体流速和催化剂用量等因素对二氯丙醇收率的影响。试验结果表明:在反应温度120℃,反应时间8 h,HCl气体流速2 L/min,催化剂用量(w)6%的反应条件下,二氯丙醇收率可达86.3%。采用生物基甘油替代烃类原料生产二氯丙醇工艺可行、成本较低。     

甘油催化氯代合成环氧氯丙烷催化剂及工艺研究

以甘油为原料催化合成环氧氯丙烷,开发了一种新型催化剂,催化剂为带羧基侧基的高分子聚合物,主链有酮基、砜基等功能基团,其氯代反应的催化活性及选择性高(无1,2,3-三氯丙烷生成,1,3-二氯-2-丙醇选择性>94%),在反应介质中稳定,回收再生方便,可重复使用.在反应温度110℃、催化剂用量为5%(对甘油质量)时二氯丙醇的收率可达到98%.当碱液质量分数为25%、碱与二氯丙醇的摩尔比为1.02:1、反应温度为55℃、搅拌反应1 h时,环氧氯丙烷的粗收率达到91%,纯度达到96%,经精馏后纯度可达到99.8%.     

以生物甘油为原料制备环氧氯丙烷的研究

以生物甘油为原料,经氯化反应和环化反应制备了环氧氯丙烷。首先以生物甘油为原料、以氯化氢气体为氯化剂、以己二酸为催化剂,采用无水Na2SO4除水4次,制得二氯丙醇（DCP）,氯化收率达90.09%;再以二氯丙醇和氢氧化钠反应制得环氧氯丙烷,通过单因素实验,得到环化反应的最佳工艺条件为：反应时间30min、氢氧化钠与二氯丙醇摩尔比1.15∶1、反应温度95℃,在此条件下的环化收率为88.2%。     

有机酸催化甘油法制备二氯丙醇的反应研究

本文对有机酸催化甘油法制备环氧氯丙烷中间体二氯丙醇的反应过程进行研究。通过考察反应产物随时间的变化，探讨了离去基团和催化剂对反应性能的影响，认为该反应主要按双分子亲核取代机理进行，选择酸性强的有机酸做催化剂，可使羟基转变为离去能力更大的基团以促进反应。碳链长度C4-C8的二元酸催化性和选择性较佳，采用己二酸为催化剂时，二氯丙醇产量可至85％。     

甘油氯化制备二氯丙醇工艺的研究

在固定床反应器中考察了各种因素对于甘油氯化反应的影响。结果表明,甘油氯化的最佳条件为:反应温度为100~110℃,催化剂为无水乙酸,催化剂在甘油中的质量分数为7%,甘油流速为0.6 mL/min,在此条件下,二氯丙醇的最高收率可达85.5%。     

甘油法制备环氧氯丙烷中间体二氯丙醇催化剂的研究

对甘油制环氧氯丙烷中间体二氯丙醇的催化剂进行了研究。考察了以冰醋酸、草酸、丁二酸、己二酸、辛酸五种有机酸为催化剂时,时间、温度、催化剂用量对目的产物二氯丙醇的收率以及反应速率的影响。研究结果表明,以己二酸为催化剂,甘油用量为3mol/kg,反应温度为110℃,反应时间为3h左右时达到平衡,二氯丙醇收率可达到85%。     

羧酸酯还原制备醇的方法研究进展

羧酸酯还原成醇是有机化学中的一类重要反应,有着广泛的用途。在涉及此类还原反应的已有文献资料中,所使用的还原体系包括硼烷、氢化铝锂、二异丁基氢化铝、红铝、金属硼氢化物等,其中,这些体系的还原能力各不相同。本文简要介绍了以上不同还原体系的研究新进展,综述了不同还原体系用于酯还原反应的反应机理,并通过不同还原体系间的比较与实例列举,为酯的还原研究提供了一些新的思路和方法,如还原体系的投料配比、投料顺序及与不同添加剂的配伍均可影响反应结果,使部分反应的收率高达90%以上,并使酯还原成醇的反应以更温和的方式进行。指出反应选择性更好,适用范围更广,反应条件更温和的新试剂、新方法将不断涌现,这将会给羧酸酯还原的领域带来更新的发展。     

Chemical modification of polynorbornene: transformation of ester moiety containing polynorbornene to carboxylic acid structure

Polynorbornene (PNB) having methyl ester in side chain was partially hydrolyzed under alkaline condition in mixed organic solvents containing tetramethylammonium hydroxide as a base. Through hydrolysis of methyl ester group in PNB under basic condition, PNB having carboxylic acid can be obtained and degree of hydrolysis (DH) were evaluated by ¹H NMR measurement from 0.1 to 0.8, depending upon reaction conditions such as reaction time, solvent, and amount of base. The resulting hydrolyzed PNB were characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, and size exclusion chromatography. No remarkable decreasing of molecular weight was observed and chain scission does not occur during the hydrolysis of PNB in the reaction condition examined here. The glass transition temperature of hydrolyzed PNB increased with increase in DH which can be attributed to the existence of intermacromolecular association of carboxylic acid in hydrolyzed PNB. Esterification of PNB having carboxylic acid was also carried out by using alkyl halide and DBU.     

Structural Analysis of Partial and Total Esters of Glycerol Undecenoate and Diglycerol Undecenoate

The direct esterification reaction between glycerol and undecylenic acid or between diglycerol and undecylenic acid generates all the possible types of glycerol or diglycerol esters. Purification by silica gel chromatography resulted in the isolation of each of these types of ester in a pure form. The molecular structures of the compounds isolated were characterized and identified by mass spectrometry, ¹H NMR, ¹³C NMR and DEPT‐135. We then studied the composition of esters of undecylenic acid formed with glycerol or diglycerol as a function of their reaction conditions, which constitute a highly complex system. We purified undecylenic acid esters from each polyol family to allow the structural identification of each ester of glycerol and each ester of diglycerol with undecylenic acid. We found that the polarity of these non‐ionic amphiphilic esters directly affected their affinity for organic and inorganic solvents and that these esters behaved very differently from anionic amphiphilic molecules, such as undecylenic acid.     

Preparation and Characterization of 4-Methoxy Cinnamoyl Glycerol

Glycerol was reacted with 4-methoxy cinnamic acid to prepare the corresponding 4-methoxy cinnamoyl glycerol. The reaction proceeded in toluene under reflux conditions with p-toluenesulfonic acid catalyst. Reaction of equimolar amounts of reactants produced the monoester in 20% yield after 2 h. The product was isolated and characterized by FTIR, mass spectrometry, and NMR techniques. Results of mass spectrometry and NMR experiments showed that the ester linkage formed between the carboxylic acid and the primary hydroxyl of glycerol. The ester displayed strong absorbance between 250 and 350 nm and shows potential as a UV filter in formulations where hydrophilic compounds are advantageous. Disclaimer The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the United States Department of Agriculture or the Agricultural Research Service of any product or service to the exclusion of others that may be suitable.     

High efficiency ester condensation using hydrophobic zeolite membranes

We successfully developed zeolite membranes with hydrophilic character, by choosing appropriate zeolites in terms of hydrophilicity and high acid tolerance. We evaluated thus developed membranes by their pervaporation (PV) performance, dehydration from acidic organic solvent. The zeolite membranes we developed, based on merlinoite (MER), chabazite (CHA) or phillipsite (PHI), are shown to exhibit stable dehydration performance, respectively. We successfully applied the membranes to the selective removal of water in an ester condensation reaction starting from a stoichiometric mixture of a carboxylic acid and an alcohol. The availability of pervaporation-assisted ester condensation reaction was validated by various kinds of combinations of carboxylic acid and alcohols, which implies the general availability of pervaporation-assisted process intensification by zeolite membranes. This paper was presented at the 11th Korea-Japan Symposium on Catatysis held at Seoul, Korea, May 21–24, 2007.     

香豆素-3-羧酸及酯合成方法的研究

在无水乙醇中,以二乙胺为催化剂,通过水杨醛与丙二酸二乙酯的Knoevenagel缩合反应合成了香豆素-3-羧酸乙酯,再经水解、酸化得到香豆索-3-羧酸。对影响香豆素-3-羧酸乙酯收率的原料配比、催化剂的用量进行了研究。所得最佳合成条件为：水杨醛与丙二酸二乙酯物质的量比1：1．2,二乙胺与水杨醛物质的量比为1：4,反应时间2h,在最佳工艺条件下。香豆素-3-羧酸乙酯的收率85％,香豆素-3-羧酸的收率95％。     

Lipase made active in hydrophobic media

Enzymes are distinguished from other catalysts by their high substrate specificity. This is a great asset when one wants to apply them for syntheses of various compounds. Their usage, however, generally is limited to hydrophilic reaction media, because they usually are not soluble and active in hydrophobic media. Recently, we have been able to make various enzymes soluble and active in highly hydrophobic organic solvents. The key to this success is the chemical modification of enzymes with an amphipathic synthetic polymer, polyethylene glycol. The activated polymers can be attached to enzymes in aqueous buffer solutions, and once enzymes are modified they become soluble and active in various organic solvents such as benzene, toluene and cholorinated hydrocarbons and exhibit high enzymic activities in these organic solvents. Modified hydrolytic enzymes catalyzed the reverse reaction of hydrolysis in organic solvents. The modified lipase catalyzed various ester synthesis reactions. Because the reactions were conducted in the pure solvent system, it also was possible to study the kinetics and the substrate specificity for ester synthesis reaction. It also catalyzed the polymerization of a hydroxy group containing carboxylic acid due to the bifunctional nature. The modified lipase catalyzed ester exchange between an ester and an alcohol, between an ester and a carboxylic acid and between two esters in organic solvents. When the two substrates for ester exchange were liquid, the reaction could take place without organic solvents. The modified lipase catalyzed an ester exchange reaction between trilaurin and triolein when dissolved in these substrates. Dilauroyl-monooleoylglycerol and monolauroyl-dioleoyl-glycerol were formed from these two substrates in the presence of the modified lipase. The modified enzyme was extremely thermostable in its substrates. In the ester synthesis and ester exchange reactions, a trace amount of water was necessary for expression of the enzymic activity. It is suggested that the amphipathic polymer molecules retained water in close proximity to the enzyme. Presented at the symposium “The Biology, Biochemistry and Technology of Lipase” at the 78th annual meeting of the American Oil Chemists’ Society held May 17–21, 1987, in New Orleans, Louisiana.     

有机叠氮化合物的合成与应用进展 Ⅱ.有机叠氮化合物在有机合成中的应用(2)

综述了近年有机叠氮化合物的合成方法及其应用。介绍了有机叠氮化合物合成中的安全性及9种合成方法,如卤化物与叠氮化试剂的取代反应,醛、羧酸、酯、醇、环氧化合物、芳香胺/杂环(芳香)胺的叠氮化反应、含叠氮基分子向目标化合物的连接反应以及醛、醇与叠氮化试剂的三组分偶联反应。阐述了有机叠氮化合物在有机合成、超分子化学、聚合物与材料科学、药物与生物技术及精细化学品等领域的应用。     

有机叠氮化合物的合成与应用进展 Ⅰ.有机叠氮化合物的合成方法

综述了近年有机叠氮化合物的合成方法及其应用。介绍了有机叠氮化合物合成中的安全性及9种合成方法,如卤化物与叠氮化试剂的取代反应,醛、羧、酯、醇、环氧化合物、芳香胺/杂环(芳香)胺的叠氮化反应,含叠氮基分子向目标化合物的连接反应以及醛、醇与叠氮化试剂的三组分偶联反应。阐述了有机叠氮化合物在有机合成、超分子化学、聚合物与材料科学、药物与生物技术及精细化学品等领域的应用。     

有机叠氮化合物的合成与应用进展 Ⅱ.有机叠氮化合物在有机合成中的应用(1)

综述了近年有机叠氮化合物的合成方法及其应用。介绍了有机叠氮化合物合成中的安全性及9种合成方法,如卤化物与叠氮化试剂的取代反应,醛、羧、酯、醇、环氧化合物、芳香胺/杂环(芳香)胺的叠氮化反应、含叠氮基分子向目标化合物的连接反应以及醛、醇与叠氮化试剂的3组分偶联反应。阐述了有机叠氮化合物在有机合成、超分子化学、聚合物与材料科学、药物与生物技术及精细化学品等领域的应用。