摘要本论文中，将聚乳酸（PLA）和不同分子量或不同添加量的乙基纤维素（EC）以物理共混的方式通过注塑机制备出PLA/EC共混试样。通过万能电子拉力试验机、扫描电子显微镜(SEM)、热重分析仪(TG)、差示扫描量热仪(DSC)等设备对试样的性能进行测试与分析。结果表明：EC的加入使得共混体系的初始热稳定性、结晶度、玻璃化转变温度和熔点均有所降低；随着EC含量和分子量的增加，拉伸强度呈逐渐降低的趋势，断裂伸长率先升高后降低，EC的加入提高了PLA/EC共混体系的韧性。71097

毕业论文关键词：聚乳酸；乙基纤维素；改性；共混

Abstract In this paper, blend films of poly(lactic acid) (PLA) and ethyl cellulose (EC) with different molecular weight or different additions were prepared through the injection molding machine in physical blending way. The performance of the samples was tested and analyzed by universal electronic tensile testing machine, SEM, TG and DSC. The results show that the initial thermal stability, crystallinity, glass transition temperature and melting point of the blends were decreased by the addition of EC; With the increase of EC content and molecular weight, the tensile strength decreased gradually, the elongation at break increased first and then decreased. The addition of EC increased the toughness of PLA / EC blends.

Key words: poly（lactic acid）; ethyl cellulose; modification; blend

目  录

1 绪论 1

1.1 化工原料 1

1.1.1 化工原料的分类 1

1.1.2 石油资源的现状 1

1.2 环境污染 2

1.2.1 环境污染分类 2

1.2.2 化工过程对环境的污染 2

1.2.3 化工产物对环境的污染 3

1.3 生物可降解高分子材料 3

1.3.1 生物可降解高分子材料的简介 3

1.3.2 生物可降解高分子材料的降解机理 3

1.3.3 生物可降解高分子材料的分类 4

1.4 聚乳酸 4

1.4.1 聚乳酸简介 4

1.4.2 聚乳酸的性能 5

1.4.3 聚乳酸的制备 6

1.4.4 聚乳酸的改性 6

1.4.5 聚乳酸的应用 8

1.5 选题思路 9

2 实验部分 11

2.1 实验原料及实验设备 11

2.2 实验过程 11

2.2.1