共查询到20条相似文献,搜索用时 78 毫秒
1.
一水合硫酸氢钠催化合成乙酸异戊酯 总被引:7,自引:0,他引:7
以一水合硫酸氢钠为催化剂催化合成了乙酸异戊酯,探讨了酯化反应条件,酯收率达97.2%。实验结果表明一水合硫酸氢钠催化性能优良,反应条件温和,方法简便,收率优良。 相似文献
2.
本文研究了一水合硫酸氢钠催化合成食用香料己酸异戊酯的反应.通过考察原料配比、催化剂用量及催化剂重复利用次数、反应时间、带水剂用量等因素对反应的影响,确定了最佳的反应条件为:酸醇物质的量的比n(己酸):n(异戊醇)=1:1.2,当己酸为0.2 mol时,反应的催化剂用量为0.5 g,反应时间为60min,所得产物酯的产率可到99.5%.提出了一水合硫酸氢钠催化酯化的反应机理,并在相同的反应条件下,利用一水合硫酸氢钠催化合成了其它类型的四种酯,其酯化率在98.3%~98.7%之间.通过对一水合硫酸氢钠催化性能的研究,结果表明:一水合硫酸氢钠是催化酯化反应适宜的催化剂. 相似文献
3.
硫酸氢钠催化合成乙酸环己酯 总被引:7,自引:0,他引:7
在水合硫酸氢钠存在下,由环己醇和乙酸合成了乙酸环己酯、乙酸、环己醇和硫酸氢钠的摩尔比为0.50:0.22:0.0145,环己烷为溶剂,回流分水100min,酯收率可达89%。 相似文献
4.
十二水合硫酸铁铵催化合成乙酸正丁酯 总被引:2,自引:0,他引:2
以十二水合硫酸铁铵和催化剂催化合成了乙酸正丁酯,了优化反应条件,酯收率达97.7%,优化反应条件如下:醇酸摩尔比为1:1.2,催化剂用量为2.5-3.0g,反应温度103-122℃。实验结果表明十二水合硫酸铁铵催化性能优良,条件温和,方法简便,收率高。 相似文献
5.
以均匀设计安排实验,在一水合硫酸氢钠催化下.利用高压微波技术,快速合成了对硝基苯甲酸乙酯。实验结果经过优化组合,得出最佳反应条件为:醇酸物质的量比为3:1,催化剂用量为1.0g,微波时间为9min,微波功率为522W.产率达99.1%。 相似文献
6.
一水合硫酸氢钠催化合成乙酸正丁酯 总被引:1,自引:1,他引:0
以一水合硫酸氢钠为催化剂,冰乙酸与正丁醇为原料合成了乙酸正丁酯。最佳合成条件:以0.2mol冰乙酸为准.醇酸摩尔比为1.3,催化剂用量为1.0g,反应时间为30min,酯收率达94.09%。 相似文献
7.
用一水合硫酸氢钠催化硬脂酸与正己醇的酯化反应合成了硬脂酸己酯。考察了催化剂用量、醇酸摩尔比、反应时间对酯化反应的影响。在典型反应条件下(正己醇与硬脂酸摩尔比=1.5:1,0.6g催化剂/0.2mol硬酯酸,反应时间2.5h),转化率为99.64%,酯化率为99.55%,产品收率为99.66%。 相似文献
8.
一水合硫酸氢钠催化合成丙酸苄酯的研究 总被引:1,自引:0,他引:1
用一水合硫酸氢钠催化苯甲醇与丙酸的酚化反应合成了丙酸苄酚。研究结果表明:一水合硫酸氢钠具有较高的催化活性。考察了催化剂用量、苯甲醇与丙酸摩尔比、反应时间、反应温度和带水剂环己烷用量对丙酸苄酚收率的影响。在典型反应条件下(苯甲醇与丙酸摩尔比=0.1:0.2,1.0g催化剂/0.2mo1丙酸,反应时间2.5h,反应温度95一110℃,15mL环己烷/0.2mo1丙酸),丙酸苄酚的收率可以达到82.3%。该催化剂易于回收且可重复使用,具有良好的活性及稳定性,是合成丙酸苄酚的理想催化剂。 相似文献
9.
10.
以一水合硫酸氢钠为催化剂,间苯二酚和乙酰乙酸乙酯为原料,通过Pechmann缩合反应,在无溶剂条件下合成了7-羟基-4-甲基香豆素。探讨了反应温度、反应时间、催化剂用量及原料配比等因素对产品收率的影响。实验表明,一水合硫酸氢钠是合成7-羟基-4-甲基香豆素的良好催化剂,正交实验法得出反应的最优条件为:反应温度为110℃,反应时间40min,/Z(间苯二酚):n(乙酰乙酸乙酯)=1:1.2,催化剂用量为0.300g(间苯二酚物质的量为0.010mol)时,产品的收率为81.3%。 相似文献
11.
我国脂肪酸的生产和应用 总被引:3,自引:0,他引:3
陆蠡珠 《精细与专用化学品》2007,15(1):24-28
简要介绍脂肪酸的分类、原料来源、生产工艺、品种以及用途。并对我国脂肪酸的生产现状进行了分析。重点介绍了脂肪酸在我国橡胶工业中、塑料助剂等领域的应用,脂肪酸甲酯作为表面活性剂在不同领域的广泛应用,最后还简述了癸二酸和改性醇酸树脂应用。 相似文献
12.
酸液体系的研究现状分析和现场应用 总被引:1,自引:0,他引:1
酸化解堵与压裂改造相比,它具有施工相对简单和成本相对较低等特点,所以酸化解堵是一项各油田广泛使用的油气田增产技术。酸化解堵技术已有将近100历史,现已研制出具有不同特点的酸液体系,如乳化酸、泡沫酸、固体酸、多氢酸等,基本能满足复杂地质条件对酸液的要求。 相似文献
13.
14.
介绍了磷钼杂多酸的合成。通过正交试验探讨了反应物料量比、三氧化钼浓度、反应温度和反应时间对产物产率的影响。结果表明,最适宜的反应条件为:反应物量比n(三氧化钼)∶n(磷酸)=12∶1.0、反应温度t=70℃、反应时间7 h、三氧化钼与水的质量比1∶8。经红外光谱分析及熔点测定确定所得产品为磷钼杂多酸化合物。并以磷钼杂多酸取代硫酸作催化剂制备乙酸乙醋来研究其催化活性,并与硫酸做催化剂进行对比实验收率为70.75%,超过硫酸催化剂水平。 相似文献
15.
The Growth‐Inhibiting Effects of Beef Fatty Acids on MCF‐7 Cells Are Influenced Mostly by the Depot Location and Inconsistently by the Biohydrogenation Intermediate Content 下载免费PDF全文
Payam Vahmani David C. Rolland Katherine E. Gzyl Danica D. S. Baines Michael E. R. Dugan 《Lipids》2018,53(7):699-708
Biohydrogenation intermediates (BHI) including conjugated linoleic acid (CLA) isomers are formed during ruminal biohydrogenation of polyunsaturated fatty acids (PUFA) in ruminants. Although many studies have examined the anticarcinogenic effects of CLA, few studies have reported the anticarcinogenic properties of BHI in their natural form found in dairy and beef fats. The present study compared the growth‐inhibitory effects of fatty acids from beef perirenal fat (PRF) or subcutaneous fat (SCF) with low or high levels of BHI in MCF‐7 human breast cancer cells. Cells were exposed for 72 h to media containing increasing doses (50 to 400 μM) of different beef fat treatments. Fatty‐acid analysis showed that BHI were readily incorporated into cell phospholipids (PL) in a treatment‐dependent manner, but higher BHI in PL did not consistently inhibit growth. Culturing with low‐BHI PRF or high‐BHI PRF did not lead to growth inhibition, but low‐BHI SCF inhibited growth, and inhibition was further increased by high‐BHI SCF. Other classes of fatty acids may, therefore, be interacting with BHI resulting in differential effects on growth inhibition in human breast cancer cells. 相似文献
16.
Claudio Guilherme Portela de Carvalho Luana Fernanda Mazzola José Marcos Gontijo Mandarino Flávio Carlos Dalchiavon José Lopes Ribeiro Aluisio Brigido Borba Filho Alberto Donizete Alves 《Journal of the American Oil Chemists' Society》2019,96(9):1019-1025
This study aimed to verify whether the fatty acid profiles of mid-oleic genotypes grown in the tropical region of Brazil fit the Codex Alimentarius and to examine the possibility of using traditional inbred lines to produce high-oleic hybrids. For this purpose, we assessed the fatty acid profile of six mid-oleic hybrids grown in environments with different minimum temperatures during oil formation in the achenes. The tests were conducted between 2015 and 2017 in an experimentally randomized complete block design with four replications. The oleic, linoleic, palmitic, and stearic acid contents were determined using gas chromatography. The mid-oleic hybrids presented varying levels of fatty acids, with oleic acid ranging between 43.6% and 84.6%, linoleic acid between 8.5% and 45.6%, palmitic acid between 3.9% and 5.7%, and stearic acid between 2.2% and 6.2%. Some of the fatty acid values were outside the ranges established by the CODEX STAN 210-1999 and were characteristic of high-oleic type sunflowers. This finding shows that we can take advantage of the potential of combining traditional inbred lines to produce high-oleic hybrids for faster and more economical breeding programs in these environments. 相似文献
17.
Claudio Guilherme Portela de Carvalho Luana Fernanda Mazzola Andressa Caldeira Flávio Carlos Dalchiavon José Marcos Gontijo Mandarino 《Journal of the American Oil Chemists' Society》2019,96(7):789-794
The objective of this work was to evaluate the quality of the oil extracted from sunflower achenes grown in Campo Novo de Parecis, the main producing region of Brazil, to optimize its use by the processing and food industries. In addition, the fatty acid profiles of the oil were checked for their adherence to the CODEX STAN 210–1999. Traditional and high-oleic genotypes were grown between 2014 and 2017 during trials with a randomized complete block experimental design with four replications. The contents of oleic, linoleic, palmitic, and stearic acids were determined using gas chromatography. The fatty acid profiles of traditional genotypes were observed to be outside the ranges established by the CODEX, with an oleic acid content above 39.4% and linoleic, palmitic, and stearic acid values lower than 48.3%, 2.7%, and 5.0%, respectively, as well as high-oleic sunflower oil with a stearic acid content of less than 2.6%. The availability of this information can, on the one hand, positively impact industries and encourage the use of better quality raw materials that are more technologically and nutritionally adequate. On the other hand, the commercialization of sunflower oil with a fatty acid profile outside the ranges established by CODEX can be difficult, because the contents are out of specification due to the climatic conditions in the cropping region. 相似文献
18.
Claudio Guilherme Portela de Carvalho Matheus Felipe da Silva José Marcos Gontijo Mandarino Anna Karolina Grunvald Nilza Patrícia Ramos José Lopes Ribeiro Vicente de Paulo Campos Godinho 《Journal of the American Oil Chemists' Society》2018,95(1):61-67
This study aimed to evaluate the fatty acid profiles of sunflower oil extracted from hybrid grains produced and stored in different environments. The trials were conducted in Teresina (Piauí), Vilhena (Rondônia), and Jaguariúna (São Paulo) in randomized complete block design with 4 replicates. After harvesting, grains from 1 high oleic and 3 traditional hybrids were packed in kraft paper bags and stored in a covered shed and in a cold chamber up to 12 months. The fatty acid profiles were determined by gas chromatography after 0, 4, 8, and 12 months of storage. Analyses of variance were conducted in a split‐plot design, with hybrids being considered as whole plots and storage times as subplots. Tukey's test was performed to compare hybrids and regression analyses for storage times. The initial fatty acid profile of the grains of the same hybrid varied depending on the production location. The grain storage of high oleic and traditional sunflower hybrids during 12 months in covered shed and in cold chamber resulted in little changes in oil fatty acid profiles, regardless of the initial contents. These changes occurred only for linoleic and palmitic acids. 相似文献
19.
丘宝增胡静怡汤吉海等 《化工时刊》2014,(2):1-4
采用廉价的浓硫酸为催化剂,氧气为自由基捕集剂,以十二酸为原料,经氯化合成α-氯代十二酸。系统考察了反应温度、催化剂用量、氯气流量、氧氯比、反应时间等因素的影响,得到最佳工艺条件:十二酸20 g,在反应温度135℃、催化剂10%、氯气流量50 mL·min-1、vO2/vCl2=1∶2、反应时间3 h,可实现十二酸基本完全转化,目标产物α-氯代十二酸选择性达到94.5%。 相似文献