论文总字数：15532字

摘 要

乙酸异戊酯是一种没有颜色且澄清透明的中性液体,在日常生活中它存在于许多水果之中,在商业生产中它被添加在许多食用香精配方中。同时,乙酸异戊酯在制革、人造丝绸、橡胶和纺织等工业上用作有机溶剂。在工业生产中,直接酯化法常常被使用来催化合成乙酸异戊酯,这种方法以浓硫酸作催化剂,但此法的不足之处有:反应速率低下、产品纯度不高、容易腐蚀损坏设备和污染环境等。所以,我们想要选用比浓硫酸更完美的催化剂。从本世纪初开始,国内外许多科学家开发出了用于酯化反应的多种新型的催化剂。固体酸催化剂就是其中之一。固体酸催化剂具有反应物分离方便、高效环保等优点,是当今催化行业发展的重点。

本文以H₃PO₄₀W₁₂XH₂O/SiO₂为催化剂,以冰醋酸和异戊醇为原料,环己烷为带水剂,催化合成乙酸异戊酯,研究了反应物摩尔比、催化剂用量、反应时间、带水剂用量及催化剂反复使用次数对反应酯化率的影响。实验结论所得此反应最佳条件:醇酸摩尔比为1.4:1,催化剂用量为冰乙酸的5%,反应时间2.5h,带水剂使用12mL,催化剂可以重复使用4次,此时乙酸异戊酯的酯化率可达73%。在优化了实验条件之后,乙酸的酯化率得到了提高,并具有多种优点,比如节约原料和催化剂用量、无环境污染、无设备腐蚀等。从实验结论可以看出,H₃PO₄₀W₁₂XH₂O/SiO₂是一种高效的、低成本的绿色催化剂,在工业上具有很高的发展价值。

关键词：乙酸异戊酯 二氧化硅 负载 磷钨酸 催化

Synthesis of Isoamyl Acetate Catalyzed by H₃PO₄₀W₁₂XH₂O/SiO₂ Solid Acid

Abstract

Isoamyl acetate is a neutral liquid with no color and clarity and clarity. It is present in many fruits in daily life and is added to many flavored flavors in commercial production. At the same time, isoamyl acetate in tannery, artificial silk, rubber and textile industries as organic solvents. In the industrial production, the direct esterification method is often used to catalyze the synthesis of isoamyl acetate, The catalyst used for the preparation of isoamyl acetate is concentrated sulfuric acid, but the drawbacks of this method are: low reaction rate, product purity is not high, easy to corrode damage Equipment and pollution of the environment. So, we want to use better catalyst than sulfuric acid . From the beginning of this century, many scientists at home and abroad have developed a variety of new catalysts for the esterification reaction. Solid acid catalyst is one of them. Solid acid catalyst has the advantages of convenient separation of reactants, green pollution and other advantages, is the focus of today's catalytic industry development.

In this paper, H₃PO₄₀W₁₂XH₂O/SiO₂ was used as catalyst to synthesize isoamyl acetate with glacial acetic acid and isoamyl alcohol as raw materials and cyclohexane as carrier agent.In this paper, Alkyd content ratio, catalyst dosage, reaction time, the amount of water carrying agent and the number of times of repeated use of catalyst on the esterification rate were studied. We obtained the conclusion that the optimum reaction conditions for the synthesis of isoamyl acetate are: the molar ratio of alkyd to acid is 1.4: 1, the amount of catalyst was 5% of glacial acetic acid, the reaction time was 2.5h, the water use agent was 12mL, the number of times the catalyst can be reused is 4 times, and the esterification rate of this reaction is 73%.After improving the synthesis conditions of this experiment, the esterification rate of the reaction was improved, and has many advantages, such as saving raw materials and catalyst dosage, no environmental pollution, no equipment corrosion. From the experimental conclusions can be seen, H₃PO₄₀W₁₂XH₂O/SiO₂ is an efficient, low-cost green catalyst, in the industry has a high development value.

Key words: Isoamyl acetate;Silica;Load;Phosphotungstic acid;Catalytic

目 录

摘要 I

ABSTRACT II

第一章 文献综述 1

1.1引言 1

1.2固体超强酸催化剂的特点 1

1.3杂多酸的特点以及对杂多酸进行负载化的原因 1

1.4固体超强酸催化剂的研究进展 2

1.5提高产率的方法 2

1.6总结 3

第二章 乙酸异戊酯的合成与结构表征 4

2.1引言 4

2.2实验部分 4

2.2.1主要试剂 4

2.2.2主要仪器 5

2.2.3磷钨酸的合成 5

2.2.4二氧化硅负载磷钨酸的制备 5

2.2.5乙酸异戊酯的合成 6

2.3结构表征 6

2.3.1磷钨酸的红外光谱分析 6

2.3.2乙酸异戊酯的红外光谱分析 7

2.4本章小结 7

第三章 反应条件对酯化率的影响 9

3.1引言 9

3.2醇酸摩尔比对酯化率的影响 9

3.3催化剂用量对酯化率的影响 10

3.4反应时间对酯化率的影响 11

3.5带水剂环己烷用量对酯化率的影响 11

3.6催化剂重复使用次数对酯化率的影响 12

3.7本章小结 12

第四章 结论与展望 14

4.1结论 14

4.2展望 14

参考文献 16

致谢 19

第一章 文献综述

1.1引言

乙酸异戊酯是一种没有颜色且澄清透明的中性液体,在日常生活中它存在于许多水果之中,在商业生产中它被添加在许多食用香精配方中。同时,乙酸异戊酯在制革、人造丝绸、橡胶和纺织等工业上用作有机溶剂。在工业生产中,直接酯化法常常被使用来催化合成乙酸异戊酯^[1],这种方法以浓硫酸作催化剂,但此法的不足之处有:反应速率低下、产品纯度不高、容易腐蚀损坏设备和污染环境等。所以,我们想要选用比浓硫酸更完美的催化剂。从本世纪初开始,国内外许多科学家开发出了用于酯化反应的多种新型的催化剂^[3-20]。固体酸催化剂就是其中之一。固体酸催化剂具有反应物分离方便、高效环保等优点,是当今催化行业发展的重点。

1.2固体超强酸催化剂的特点

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