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1.
钛(锆)酸酯催化合成苯乙酸酯 总被引:1,自引:0,他引:1
利用钛(锆)酸酯催化剂,通过酯化或酯交换反应合成了苯乙酸苯甲酯,苯乙酸苯乙酯,苯乙酸茴香酯(酯收率为90%以上)。同时对影响反应的诸因素进行了讨论。 相似文献
2.
苹果酯和苹果酯-B的合成研究 总被引:53,自引:0,他引:53
用多种氯化物催化合成苹果酯和苹果酯-B,发现无水三氯化铝和三氯化铁是合成苹果酯和苹果酯-B的良好催化剂,氯化物催化活性序为:三氯化铝>三氯化铁>氯化铜>氯化锌。 相似文献
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以麦芽酚和丙酰氯为原料,合成了丙酸麦芽酚酯,并考查了反应温度和反应时间对丙酸麦芽酚酯收率的影响,确定了反应优化条件为反应温度60-70℃,反应时间3h。以麦芽酚、乙基麦芽酚和丁酰氯为原料,分别合成了丁酸麦芽酚酯和丁酸乙基麦芽酚酯。以FTIR、GC—MS确定了产品的结构。 相似文献
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聚乳酸是一种重要的生物医用高分子材料,一般由中间体丙交酯开环聚合得到。合成丙交酯的收率是影响聚乳酸大规模生产及降低生产成本的关键因素。丙交酯的制备方法主要有减压法和常压气流法。在合成丙交酯的过程中,低聚体解聚为丙交酯的反应是在高温下进行的,很容易造成乳酸低聚体炭化变黑,导致丙交酯的收率大大降低。 相似文献
5.
硼酸酯类偶联剂的合成 总被引:3,自引:0,他引:3
本文报道以价廉易得的原料、简单可行的路线合成硼酸酯之结果。在理论分析的基础上,采用反应一精馏一体化法合成了硼酸三异丙酯,确定了带水剂,考察了原料配比、带水剂浓度对收率的影响,原料配比、浓硫酸催化剂对反应速率的影响。进而以硼酸三异丙酯为中间体,运用酯交换法合成了硼酸酯偶联剂,所确定的合成方法具有操作简便、产品收率高等优点。 相似文献
6.
有机钛化合物有着极为广泛的用途,它可作为偶联剂、酯化反应催化剂和涂料、粘接剂、皮革制剂的添加剂,而其主要指的是钛酸酯类的化合物[1]。一般将结构为(RO)4Ti的称为对称钛酸酯;而将(RO)。TiORf称为不对称钛酸酯。若在RfO-上有活性基团,便可以把钛酸酯以价键的形式连接在某些高分子聚合物或有机物上,从而改善钛酸酯偶联剂的性质。过去,人们常采用控制TICI4和醇的摩尔比来合成不对称钛酸酯:此路线合成比较困难,产品难以纯化,收率极低。我们采用如下的合成路线:以较高的收率制得了4个新的含氟钛酸酯,并对它们的性质进… 相似文献
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本文报道合成(RO)3TiOR'一类钛酸酯的合成路线和方法。合成了四个新的含氟钛酸酯,并对它们的性质进行了初步的研究。 相似文献
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探讨了以往合成乙二醇硬脂酸酯文献资料的若干问题,采用正交实验对影响乙二醇硬脂酸酯合成的因素进行了分析,并采用自制负载型催化剂合成了一系列不同含量的单酯和双酯,产品符合行业标准QB/T 4312-2012的指标要求,催化剂用量少且能多次重复利用。 相似文献
10.
本文研究了新洁而灭在邻苯二甲酸丁芒酯、苯甲酸苄酯、醋酸苄酯、甲酸苄酯合成中的催化作用,其对于原料或产品不易不解的苄酯合成有较好的催化效率,新洁而灭无毒、高效,是理想的相转移催化剂。 相似文献
11.
Gladys H. P. Cho S. K. Yeong T. L. Ooi C. H. Chuah 《Journal of surfactants and detergents》2006,9(2):147-152
Mono- and di-esterified glycerols were synthesized by the base catalyzed reaction of glycerol with aliphatic dicarboxylic
acid esters (C2−C9): 2,3-dihydroxy-propyl oxalate (2), 1,3 dioxalyloxy propan-2-ol (3), 1,3-dimethoxyoxalyloxy propan-2-ol (5), 2,3-dihydroxy-propyl malonate (6), 2,3-dihydroxy-propyl methyl malonate (7), 2,3-dihydroxy-propyl methyl succinate (8), 1,3-dimethoxysuccinyloxy propan-2-ol (9), 2,3-dihydroxy-propyl methyl glutarate (10), 1,3-dimethoxyglutaryloxy propan-2-ol (11), 2,3-dihydroxy-propyl methyl azelate (14), and 1,3-dimethoxyazelyloxy propan-2-ol (15). Their structures were elucidated by spectrometric methods. Compounds 8, 10, 2,3-dihydroxy-propl methyl adipate (12) and 14 were found to possess surface active properties and the ability to reduce the interfacial tension between paraffin and water. 相似文献
12.
Cleavable surfactants 总被引:6,自引:0,他引:6
Per-Erik Hellberg Karin Bergström Krister Holmberg 《Journal of surfactants and detergents》2000,3(1):81-91
Cleavable surfactants are of interest for several reasons. Above all, the development of surfactants with weak bonds deliberately
built into the structure is driven by the need for improved biodegradability of amphiphiles. The breakdown may be catalyzed
by enzymes, and biodegradation would be the normal mechanism in sewage plants. Alternatively, the surfactant may degrade by
chemical means, e.g., induced by acid, alkali, ultraviolet (UV) light, heat, or ozone. Acid- and alkali-labile surfactants
have attracted particular attention, and there is often a compromise between required stability at one stage and ease of breakdown
at a subsequent stage. The paper reviews the main routes used to prepare cleavable surfactants and points out advantages and
disadvantages of the different approaches. Emphasis is placed on the development during recent years. Cyclic and acyclic acetals,
ketals, and ortho esters are the most important types of bonds for the preparation of acid-labile surfactants, whereas alkali-labile
amphiphiles usually are based on ester bonds. The ester bond approach has been particularly important for cationic surfactants,
and so-called ester quats have rapidly taken a large share of the traditional market for quats. Betaine esters constitute
a special class of ester with very pronounced pH dependence. UV-labile surfactants based, for instance, on an azo bond, offer
promise for the future. 相似文献
13.
脂肪酶催化合成生物表面活性剂 总被引:4,自引:0,他引:4
脂肪酸单甘油酯、脂肪酸糖酯、聚甘油脂肪酸酯和长链脂肪酸蜡酯是重要的生物表面活性剂。传统化学法以碱为催化剂在高温下进行,不仅能耗高且产品纯度低。脂肪酶作为一种天然生物催化剂,可以温和条件下催化合成上述生物表面活性剂,能耗低且产品纯度高。综述对脂肪酶催化合成生物表面活笥剂工艺路线、反应体系及操作参数。 相似文献
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Amidination of lipase with hydrophobic imidoesters 总被引:2,自引:0,他引:2
M. Basri K. Ampon W. M. Z. Yunus C. N. A. Razak A. B. Salleh 《Journal of the American Oil Chemists' Society》1992,69(6):579-583
Lipase fromCandida rugosa was chemically modified by amidination with imidoester hydrochlorides of different hydrophobicity. The modified enzyme showed
a higher ester synthesis activity but a lower ester hydrolysis activity compared with the native enzyme. The maximum specific
activity of the modified enzyme depended on its degree of derivatization. Benzene was found to be the best solvent for the
synthesis reaction. The optimal temperature for the reaction was not affected by modification of the lipase. The modified
lipase was more thermostable and solvent-stable than the native enzyme. When fatty acids of different carbon chainlength were
tested as substrates in the synthesis of esters with the modified lipase, the highest activity was observed with myristic
acid and propanol. 相似文献
17.
提出一种合成对氟、3,5-二氟(氯)苯膦酸酯的有效方法。通过对氟溴苯、3,5-二氟溴苯(均三氯苯)与亚磷酸三甲酯在光照下反应,得到相应的苯膦酸酯。对合成的苯膦酸酯进行了质谱和核磁(1H NMR)表征,并考察了反应条件(反应物投料比、反应温度、反应时间)对转化率的影响。研究发现,与均三氯苯为原料相比,含氟溴苯具有更高的选择性(氟不参与反应),在一定反应下,可以得到中等的3,5-二氟苯膦酸酯转化率(42.5%)和收率(33.6%)。得到的对氟、3,5-二氟苯膦酸酯很容易从产物中分离。此外,在相同反应条件下,以对氟溴苯、3,5-二氟溴苯、或者均三氯苯为原料,转化率基本相同。 相似文献
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