2015届毕业论文
题目干法制备羧甲基淀粉
专业班级化工04班
学号1106010409
学生姓名刘玉洁
学院化工与制药学院
指导教师金士威/欧阳贻德
指导教师职称教授/讲师
完成日期：2015 年 6 月8 日
干法制备羧甲基淀粉Dry Process Preparation of
Carboxymethyl Starch
学生姓名刘玉洁
指导教师欧阳贻德/金士威
摘要
羧甲基淀粉（CMS)是一种非常重要的阴离子型醚化淀粉，其用途十分广泛。
当今社会对其需求量的日益增大，对其性能要求越来越高，对羧甲基淀粉的研究已逐步受到关注，目前，羧甲基淀粉的生产工艺存在诸多问题，不能完全满足工业生产需要。
以玉米淀粉为原料，采用干法制备高取代度的羧甲基淀粉。
反应分为碱化和醚化2个阶段，以异丙醇（体积分数为60%）为溶剂，氢氧化钠为碱化剂，氯乙酸钠为醚化剂，对羧甲基淀粉工艺进行了研究。
考察了碱化温度、碱化时间、醚化温度、醚化时间等因素对羧甲基淀粉取代度的影响，最终确定最佳的碱化温度为35℃，碱化时间为60min，醚化温度为70℃，醚化时间为150min，在此条件下制得的羧甲基淀粉的取代度为0.32，产品的外观得到改善，淀粉糊的黏度稳定性得到加强。
关键词：羧甲基淀粉；干法；制备；取代度；醚化
Abstract
Carboxymethyl starch (CMS) is an important kind of anionic etherified starch, and is widely applied in many areas. With the increasing demand of society, people have paid more attention to study carboxymethyl starch gradually, which has become a hot spot in recent years. Currently, there is a low degree of substitution, the viscosity instability of the starch paste, poor appearance and other shortcomings on the industrial production of carboxymethyl starch and therefore that greatly limits its application.
Highly substituted carboxymethyl starch was produced by dry method used corn starch as raw material. The process was made up of two steps, that was the alkalizing reaction and the etherifying reaction. The isopropyl alcohol （whose volume fraction was 60%)was used as a solvent, alkalizing agent was sodium hydroxide and the etherifying agent was sodium chloroacetate. The effects of the alkalizing temperature and reaction time, the etherifying temperature and reaction time on the degree of substitution were considered.Ultimately, the best alkalizing temperature is 35 ℃, the reaction time is 60 minutes,the etherifying temperature is 70 ℃and the reaction time is 150 minutes. Under the above conditions, the degree of substitution of carboxymethyl starch can reach 0.32, and the appearance of the product has improved, the viscosity stability of starch paste has been strengthened too.
Keywords: carboxymethyl starch; dry method; preparation; degree of substitution; etherification
目录
摘要 (I)
Abstract (II)
引言 (1)
第1章文献综述 (2)
1.1淀粉 (2)
1.1.1淀粉的分子结构及性质 (2)
1.1.2淀粉的颗粒结构 (4)
1.1.3淀粉的糊化与老化 (4)
1.2改性淀粉 (5)
1.2.1改性淀粉的概念 (5)
1.2.2改性淀粉的分类 (5)
1.2.3国内外改性淀粉的生产状况 (6)
1.3羧甲基淀粉 (6)
1.3.1羧甲基淀粉合成机理 (6)
1.3.2羧甲基淀粉制备工艺 (7)
1.3.3羧甲基淀粉的应用 (8)
第2章材料与方法 (10)
2.1实验材料 (10)
2.2主要仪器设备 (10)
2.3实验方法 (10)
2.3.1干法制备羧甲基淀粉 (10)
2.3.2试验因素 (11)
2.4取代度的测定 (11)
2.4.1取代度测定原理 (11)
2.4.2 试剂和溶液的配制 (11)
2.4.3 取代度测定步骤 (11)
第3章实验结果与讨论 (13)
3.1 碱化温度对取代度的影响 (13)
3.2 碱化时间对取代度的影响 (14)
3.3 醚化温度对取代度的影响 (15)
3.4 醚化时间对取代度的影响 (16)
第4章结论与建议 (17)
4.1 结论 (17)
4.2 建议 (17)
4.2.1 对本次实验的建议 (17)
4.2.2 对其他反应条件的建议 (17)
4.2.3对研究方向的建议 (18)
参考文献 (19)
致谢 (20)。