摘要聚乳酸由于其良好的生物相容性和生物降解性，而成为一种研究较为广泛的环境友好型聚合物。但其韧性差、抗冲击强度低、热稳定性差等缺点阻碍了它的进一步应用,因此需要对聚乳酸进行改性，扩大其应用范围。石墨烯是一种由单层碳原子紧密堆积而成的二维蜂窝状晶格结构的碳质材料，由于其特殊的结构和优异的性能受到了极大的关注。石墨烯的比表面积大，加入到树脂基复合材料中能形成良好的界面作用，因而将石墨烯加入到聚乳酸中制成复合材料，可望提高聚乳酸的性能。本论文选用三氯甲烷为溶剂，通过液相剥离的方法制备石墨烯，然后再用溶剂混合的方法制备石墨烯/聚乳酸纳米复合材料。TEM结果表明采用液相剥离法制备的石墨烯的剥离程度高，SEM结果表明石墨烯均匀的分散在聚乳酸基体中，没有明显的团聚现象。TGA分析表明石墨烯的加入提高了聚乳酸基体的热稳定性，DMA研究表明石墨烯/聚乳酸纳米复合材料高温下的力学性能有很大的提高，当石墨烯含量为0.5w%时，温度为100℃时，纳米复合材料处于橡胶态，其储能模量提高了将近30倍，即由6.87MPa提高到212.15MPa。拉力测试表明石墨烯的加入大大提高了聚乳酸的力学性能，当石墨烯含量为1w%时，拉伸强度由36.64MPa提高到51.14MPa。63613

毕业论文关键词  石墨烯  聚乳酸  液相剥离  复合材料

 毕业设计说明书（论文）外文摘要

Title  Preparation and characterization of liquid ultrasonication stripped poly(lactic acid)/graphene composites

Abstract

Nanocomposites were prepared by solution-blending of PLA with liquid-phase exfoliated graphene using chloroform as a mutual solvent. Graphene was prepared via liquid-phase exfoliation in chloroform. Transmission electron microscopy (TEM) was used to examine the quality of exfoliated graphenes (EGs). The dispersion of graphene in PLA matrix was observed by scanning electron microscope (SEM). FT-IR and Raman spectroscopy indicate that the structure of EGs is intact and EGs can act as good reinforcement fillers in the polymer matrix. Thermo gravimetric analyzer (TGA) revealed that the addition of graphene sheets greatly improve the thermal stability of the composite material. Dynamic mechanical analysis shows that the storage modulus (E’) of the resulting PLA/EGs nanocomposites increased by about 30 times at 100 ℃from 6.87 (pure PLA) to 212.15 MPa (PLA/EGs-0.5). Moreover, tensile strength of PLA/EGs nanocomposites is much higher than that of PLA homopolymer, increasing from initial 36.64 MPa (pure PLA) up to 51.14 MPa (PLA/EGs-1.0 ).

Keywords  Graphene, PLA, Liquid-phase exfoliation, Tensile strength

目次

1 引言 1

1.1聚乳酸概述 1

1.2 石墨烯概述 2

1.2.1石墨烯的结构和性能 2

1.2.2 石墨烯的制备 2

1.3 石墨烯/聚合物基纳米复合材料 4

1.3.1聚合物基纳米复合材料 4

1.3.2 石墨烯/聚合物基纳米复合材料的制备 4

1．4研究目的 6

2 实验部分 7

2.1 实验试剂和仪器 7

2.2 石墨烯的制备 7

2.3 石墨烯/PLA纳米复合材料的制备 8

2.4 测试与表征 8

2.4.1 紫外测试