摘 要

纤维素纳米晶是一种制作成本低，原料来源广泛，无污染的高分子生物材料。由于其独特的纳米结构使之具备高弹性，高刚性的材料性能，并且由于它的可再生，可降解以及生物相容性，使得它能够成为优秀的高分子材料。通过对其表面进行化学改性，合成新的材料，赋予它更多的功能，也使其在众多领域中显现出巨大的应用前景。

本课题首先用短绒棉为原料，通过硫酸水解制备纤维素纳米晶，通过查阅文献及分析，用2wt%的氢氧化钠处理短绒棉12h后，在水洗后用65wt%的硫酸在45℃水解45分钟后水洗透析得出CNC悬浮液作为下一步反应的原料。采用硅烷偶联剂，TEMPO氧化和3-MPA酯化三种不同的方法对纤维素纳米晶表面巯基化。通过对几种修饰方法的过程中实验用料，实验步骤，以及最终修饰成功的纤维素纳米晶所占比例的对比，分析各个方法的优缺点，综合出一种比较优良的方法。

关键词 ：纤维素纳米晶，巯基化反应，化学修饰

  Abstract

Nanocrystalline cellulose is a low production cost, wide source of raw materials, pollution-free polymer biomaterials. Because of its unique nano-structured to have high flexibility, high rigidity of the material properties, and because it is renewable, biodegradable and biocompatible, so that it can become an excellent polymer materials. By its surface chemical modification, the synthesis of new materials, giving it more functionality, but also to show potential application in many fields.

   After this first issue with short staple cotton as raw material by sulfuric acid hydrolysis of cellulose nanocrystals prepared by literature review and analysis, with 2wt% of sodium hydroxide short staple cotton 12h, after washing with 65wt% sulfuric acid at 45 ℃ after 45 minutes, washed with water hydrolysis dialysis as a starting material was obtained suspension CNC for the next reaction. Silane coupling agent, TEMPO oxidation and esterification of 3-MPA three different methods of cellulose nanocrystals surface thiolation. By some method of modifying the course of the experiment materials, experimental procedures, and ultimately the success of the modified cellulose nanocrystals contrast proportion, advantages and disadvantages of each method, synthesize a more excellent way.

  Key Words: cellulose nanocrystals,；thiol group reactions,；chemical modification

目 录

第一章 绪论......................................................6

1.1 前言.......................................................6

1.2 天然纤维素.................................................6

1.2.1 纤维素的来源..........................................6

1.2.2 纤维素的物理化学性质..................................6

1.3 纤维素纳米晶...............................................7

1.4 国内外研究进展.............................................7

1.5 纤维素纳米晶的制备方法.....................................7

1.6 纤维素纳米晶的改性.........................................8

1.7 论文研究的目的意义及主要内容...............................8

第二章 制备纤维素纳米晶..........................................10

2.1 引言.......................................................10

2.2 部分实验...................................................10

2.2.1实验原料，药品及设备....................................10

2.2.2纤维素纳米晶的制备......................................10

2.3 测试与表征.................................................11

2.3.1透射电镜分析纤维素纳米晶形貌............................11

1. 纤维素纳米晶表面改性......................................12

3.1 引言.......................................................12

3.2 实验部分...................................................12

3.2.1 用3-MPA制备CNC-SH...................................13

3.2.1.1 实验仪器.......................................13

3.2.1.2 用3-MPA引入巯基...............................13

3.2.1.3 引入巯基后的纤维素纳米晶的形貌.................13

3.2.2 用TEMPO氧化的方法制备CNC-SH.........................14

3.2.2.1 实验仪器.......................................14

3.2.2.2 用TEMPO氧化的方法引入巯基.....................15

3.2.2.3 引入巯基后的纤维素纳米晶的形貌.................15

3.2.3 硅烷偶联剂制备CNC-SH.................................15

3.2.3.1 实验仪器.......................................15

3.2.3.2 用硅烷偶联剂引入巯基...........................16

3.2.2.3 引入巯基后的纤维素纳米晶的形貌.................16

3.3 测试与表征................................................17

3.3.1 红外光谱（FT-IR）分析................................17

3.3.2 X射线光电子能谱（XPS）分析..........................18

3.3.3 X射线衍射（XRD）分析................................19

3.4 本章小结..................................................20

第四章 结论及后续工作思考........................................22

参考文献.........................................................23

致谢.............................................................25

第一章 绪 论