论文总字数：27053字

摘 要

丙酸乙酯是一种重要的有机化学品，在医药、涂料、食品、香料等很多行业中都有广泛的使用。本文采用浸涂法制备PVA-PSSA/SA-PVA复合膜,以PVA为膜材料，PSSA为催化剂，用GA和H₂SO₄作为交联剂，制备催化渗透汽化复合膜，用于耦合酯化反应的研究。

催化层PVA：PSSA的质量比分别为5:3、5:5、5:7，分离层SA：PVA的质量比为6:4，催化膜分别刮膜厚度为6µm、15µm、21µm和27µm.。研究催化层厚度和PVA：PSSA的质量比对膜渗透性能和酸转化率的影响。催化层膜厚度越大，渗透通量越大，渗透通量逐渐从148 g/(m²·h)升高到400 g/(m²·h) 。PVA：PSSA质量比为5:3时，膜通量只有100，增加PSSA的含量，膜PV通量增加到300，继续增加PSSA含量，通量保持不变。催化层厚度从6μm增加到21μm时，反应转化率明显加快，12小时的酸转化率分别为11.4%、75.7%、90.6%，当继续增加催化层厚度时，反应速度、酸的转化率几乎不变。当质量比从5:3增加到5:7时，总体的酸转化率有明显提高，12小时的转化率分别为83%、90%、94%；但是质量比为5:7的膜在二次使用时的转化率大幅降低，可能是因为增加PSSA会有一部分分子无法包覆在PVA网状结构中，导致分子流失所致。最佳的酸醇摩尔比为1:2，膜面积反与应液体积比为1.09cm^-1。

关键词：聚乙烯醇（PVA）; 聚苯乙烯磺酸（PSSA）；渗透汽化；酯化反应

Study on esterification of propionic acid and ethanol with pervaporation by PVA-PSSA/SA-PVA composite membrane

Abstract

Ethyl propionate is an important organic chemical which widely used in medicine, paint, food, spices and other industries. In this paper, PVA-PSSA / SA-PVA composite film was prepared by coating method. PVA was used as the membrane material, PSSA as catalyst and GA and H2SO4 as crosslinking agent to prepare catalytic pervaporation composite membrane for coupling esterification reaction.

The mass ratio of PVA: PSSA is 5: 3, 5: 5, 5: 7, and the mass ratio of separation layer SA: PVA is 6: 4, and the thickness of catalyst film is 6μm, 15μm, 21μm and 27μm respectively. The effects of catalytic layer thickness and PVA: PSSA mass ratio on membrane permeability and acid conversion were investigated. The larger the thickness of the catalyst layer, the greater the permeation flux and the increasing flux from 148 g / (m² · h) to 400 g / (m² · h). The membrane flux was only 100 g / (m² · h) at PVA: PSSA mass ratio of 5: 3, and the membrane PV flux increased to 300 when the ratio rose to 5:5. Continue to increase the PSSA content, flux kept unchanged. When the thickness of the catalyst layer increased from 6μm to 21μm, the conversion of the acid was obviously accelerated. The acid conversion rate was 11.4%, 75.7% and 90.6% respectively. When the thickness of the catalyst layer was increased to 27μm, the reaction rate and acid conversion rate were almost unchanged. When the mass ratio increased from 5: 3 to 5: 7, the overall acid conversion rate was significantly improved, the conversion rate of 12 hours were 83%, 90%, 94%; but in the secondary use, the conversion rate of 5: 7 membrane is significantly reduced, which possibly due to the lossof the overmuch PSSA molecules that cannot be enbeded in the PVA network. The optimum molar ratio of propionic acid and ethanol is 1: 2, and the ratio of reaction volume to film area is 1.09cm^-1.

Keywords: polyvinyl alcohol (PVA); polystyrene sulfonic acid (PSSA); catalytic pervaporation composite membrane; esterification reaction

目录

摘 要 I

ABSTRACT II

第一章 文献综述 1

1.1 丙酸乙酯合成反应概述 1

1.1.1 丙酸乙酯的性质和用途 1

1.1.2 酸醇酯化合成丙酸乙酯 1

1.2 渗透汽化技术 1

1.2.1 渗透汽化简介 1

1.2.2 渗透汽化分离机理 2

1.2.3 渗透汽化膜材料 3

1.2.4 渗透汽化与酯化反应的耦合 5

1.3 PSSA-PVA催化膜 6

1.4 本文的研究目的和内容 7

第二章 PVA-PSSA/SA-PVA复合膜的制备及表征 8

2.1 引言 8

2.2 实验部分 8

2.2.1 实验药品和仪器 8

2.2.2 实验装置及步骤 9

2.2.3 分析方法 10

2.2.4 PVA-PSSA/SA-PVA复合膜的制备 12

2.2.5 PVA-PSSA/SA-PVA复合膜的表征 12

2.3 结果与讨论 13

2.3.1 复合膜XRD分析 13

2.3.2 复合膜热重分析 13

2.3.3 复合膜SEM分析 14

2.3.4 催化层厚度对膜分离性能的影响 15

2.3.5 PVA与PSSA质量比对膜分离性能的影响 15

2.4 本章小结 16

第三章 渗透汽化耦合酯化反应 18

3.1 引言 18

3.2 实验部分 18

3.2.1 实验药品和仪器 18

3.2.2 实验装置及步骤 18

3.2.3 分析方法 19

3.3 结果与讨论 21

3.3.1 催化膜厚度对丙酸转化率的影响 21

3.3.2 PVA与PSSA质量比对酸转化率的影响 23

3.3.3 丙酸与乙醇的摩尔比对酸转化率的影响 24

3.3.4 膜面积(S)与反应液体积(V)比对酸转化率的影响 25

3.4 本章小结 26

第四章 结论与展望 27

3.1 结论 27

3.2 展望 27

参考文献 27

致谢 32

文献综述

1.1 丙酸乙酯合成反应概述

1.1.1丙酸乙酯的性质和用途

丙酸乙酯分子式为C₅H₁₀O₂，它的颜色是水白色，并且这种液体还具有菠萝的气味。丙酸乙酯在水中不会溶解，但是在很多有机溶剂中能溶解。广泛应用于人造香料、食品工业、制药工业、有机合成等工业中，丙酸乙酯可以用作食品加香剂，也可以作为有机溶剂、合成中间体使用[1]。

1.1.2酸醇酯化合成丙酸乙酯

丙酸乙酯的生成反应式如下：

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