摘 要

本论文以热塑性淀粉和羧甲基纤维素为基体、氯化钙为物理交联剂、甘油为增塑剂，采用溶液浇筑成膜法制备了一系列不同交联剂用量和不同基体配比的热塑性淀粉/羧甲基纤维素复合薄膜，通过红外光谱测定、吸水率测试、拉伸试验和接触角的表征考查了Ca² 离子的添加量和基体配比对复合薄膜性能的影响。红外光谱结果表明，Ca^2＋离子与羧甲基纤维素钠分子链上的羧基形成了配位键，起到了交联作用。在50%湿度下，吸水率试验表明当Ca^2＋离子添加量为0.15g时薄膜的吸水率达到最低值，当淀粉占基体的70%时薄膜的吸水率达到最低值。拉伸性能测定结果表明，0%和50%湿度下复合薄膜的弹性模量和拉伸强度均随着Ca² 离子添加量的增加和基体配比的增加呈先上升后下降的趋势，当Ca^2＋离子添加量为0.15g时，两种湿度下复合薄膜的弹性模量和拉伸强度均达到最高值，0%湿度下分别为未添加Ca^2＋离子复合薄膜的1.57、1.56倍，50%湿度下分别为未添加Ca^2＋离子复合薄膜的1.65、1.83倍；当淀粉占基体的70%时，两种湿度下复合薄膜的弹性模量和拉伸强度均达到最高值，0%湿度下为基体配比为1：1的复合薄膜的1.27、1.23倍，50%湿度下为基体配比为1：1的复合薄膜的1.28、1.51倍，复合薄膜的断裂伸长率在0%和50%湿度下的变化幅度受Ca² 离子添加量的增加和基体配比的增加的影响较小。接触角测定结果表明，Ca² 离子用量为0.05g时复合薄膜疏水性最好。总体而言，氯化钙的添加量为13%时，淀粉含量为70%时，复合薄膜综合性能最好。

关键词：热塑性淀粉；羧甲基纤维素；复合薄膜；离子交联

Preparation and Properties of Ca² Ion Crosslinked Thermoplastic Starch/Carboxymethyl Cellulose Composite Films

In this paper, thermoplastic starch and carboxymethyl cellulose as the matrix, calcium chloride as the physical crosslinking agent, glycerin as the plasticizer, a series of thermoplastic starch/carboxymethyl cellulose composite films with different crosslinking agent dosage and different matrix proportion were prepared by the solution casting method. Through the infrared spectrophotometry, water absorption test, tensile test and the characterization of the contact Angle, the influence of the addition of Ca² ions and matrix proportion on the properties of the composite film was investigated. Ftir results indicate that the Ca² ions with sodium carboxymethyl cellulose molecular chain on the carboxyl formed the coordination bond, have the effect of crosslinking. At 50% humidity, the water absorption rate test showed that when the Ca² ion content was 0.15g, the water absorption rate of the film reached the lowest value, and when starch accounted for 70% of the matrix, the water absorption rate of the film reached the lowest value. Tensile properties determination results showed that 0% and 50% humidity elastic modulus and tensile strength of composite membrane with Ca² ions and substrate ratio increased with the increase of adding amount of a downward trend after rising first, when the Ca² ions content is 0.15 g, two kinds of humidity composite membrane elastic modulus and tensile strength reached its highest, 0% humidity not add Ca² ions composite films respectively 1.57, 1.56, 50% humidity not add Ca² ions composite films respectively 1.65, 1.83 times; When starch accounted for 70% of the matrix, the elastic modulus and tensile strength of the composite film reached the highest value under the two kinds of humidity. At 0% humidity, it was 1.27 and 1.23 times of the composite film with the matrix ratio of 1:1. At 50% humidity, it was 1.28 and 1.51 times of the composite film with the matrix ratio of 1:1. Contact Angle measurement results show that the dosage of Ca² ions is 0.05 g hydrophobic composite film is best. In general, the amount of adding calcium chloride 0.15g, the starch content was 70%, the composite film comprehensive performance is best.

Key words：thermoplastic starch;Carboxymethyl cellulose;Composite film;Ionic crosslinking

目 录

1. 绪论……………………………………………………………………………………….……1

1.1 热塑性淀粉……………………………………………………………………….….…1

1.1.1 定义…………………………………………………………………………..……1

1.1.2 发展现状………………………………………………………….……….………2

1.1.3 存在的问题…………………………………………………………….…….……2

1.1.4 热塑性淀粉的改性…………………………………………………………..……3

1.2 羧甲基纤维素……………………………………………………………………..……4

1.3 课题的研究的目的和意义…………………………………………………….…….…5

2 实验部分……………………………………………………………………………….…….…6

2.1 材料和设备……………………………………………………………………….….…6

2.1.1 主要的实验材料……………………………………………………………..……6

2.1.2 主要的实验设备…………………………………………………………….….…6

2.2 热塑性淀粉/羧甲基纤维素复合薄膜的制备………………...……..……………...…6

2.3 样品的表征…………………………………………………………………….…….…7

3 结果与讨论………………………………………………………………………….………….9

3.1 红外分析…………………………………………………………….……………….…9

3.2 吸水率分析………………………………………………………………………….....10

3.3 力学性能分析……………………………………………………………………….…12

3.4 接触角表征分析…………………………………………………………………….…16

4 结论…………………………………………………………………………………………….18

致谢…………….………………………………………………………………………………..…19

参考文献………………………………………………………………………………….……..…20

1、绪论

传统塑料薄膜以石油基为原料加工制成，耐用美观、易加工，自问世以来被广泛应用于人们的日常生活中，不过大量的使用塑料产品不仅仅危害我们的身体健康，还会带来大量的“白色垃圾”。目前全球的年塑料产量已经超过3亿吨，而且还在以高速不断增长，未来十年内可能增长至10亿吨，这些塑料的难以降解必然会引起越来越严重的环境污染问题。

全球可持续发展成为越来越多国家的共同的追求，随着环境污染的日益严重，可降解塑料的发展也受到了越来越多国家的重视。早在上世纪末，自然降解的塑料制品就已经成为了研究热门方向，由于当时的生产成本和技术等问题，遇到了发展瓶颈。近十年来，随着生产原料和生产技术的逐步提高，降解塑料又重新回到科学家的视野中，很多国家也投入更多的人力物力来研究降解塑料。