PLA-PHB碳纳米管复合材料结构与性能的研究_高分子材料与工程专业毕业论文

PLA-PHB碳纳米管复合材料结构与性能的研究_高分子材料与工程专业毕业论文

PLA/PHB/碳纳米管复合材料结构与性能的

研究

STUDY ON THE STRUCTURE AND

PROPERTY OF PLA/PHB/ CNTS

COMPOSITE

专业：高分子材料与工程

摘要

本文采用浓硝酸酸化碳纳米管，并通过正硅酸乙酯在碳纳米管表面接枝大量羟基，然后通过加入硅烷偶联剂KH550，形成表面被包覆的碳纳米管；再以聚乳酸为主体、PHB为辅料、碳纳米管为增强体,采用哈克密炼机制备PLA/PHB/碳纳米管复合材料。通过红外吸收光谱分析经碳纳米管的处理情况；采用电镜扫描分析处理过碳纳米管的分散情况以及积聚形态；采用拉伸测试、冲击测试、静弯曲测试来研究复合材料的力学性能；采用微型燃烧量热计研究复合材料的热稳定性能；采用毛细管流变仪研究复合材料的流变性能；采用维卡软化温度测试仪测定复合材料的维卡软化温度。

通过碳纳米管红外光谱分析表明，经过正硅酸乙酯和硅烷偶联剂的综合处理，在碳纳米管表面上成功的接枝了大量的官能团，并且表面包覆了有效地附着基团。

力学性能研究表明，加入弹性体PHB之后，材料的拉伸强度、冲击强度、断裂伸长率提高，静弯曲强度下降。再加入少量的碳纳米管之后，复合材料的拉伸强度、冲击强度和静弯曲强度都有很大的提升，断裂伸长率下降。但是增加碳纳米管的组分，由于这是由于碳纳米管的团聚导致与复合材料界面粘结力下降，冲击强度有所下降。

流变性能研究表明，聚乳酸加入PHB后，在低剪切速率下，体系的表观粘度增加；在较高剪切速率下，体系的表观粘度低于纯聚乳酸的，说明加入PHB 之后，体系的表观粘度更受剪切速率的影响。在加入碳纳米管之后，体系的表观粘度增大，并且碳纳米管含量越大，表观粘度也越大。

热稳定性能研究表明，加入碳纳米管之后，复合材料的热释放速率峰值有了较大的下降，并且热释放速率峰值对应的时间也有所延迟。说明碳纳米管的加入能够提高聚乳酸的热稳定性。

关键词：聚乳酸；聚3羟基-4羟基丁酸酯；碳纳米管；复合材料；

ABSTRACT

In this paper, used the nitric acid acidized carbon nanotubes, and through the tetraethyl orthosilicate(TEOS) in carbon nanotubes surface hydroxyl grafted a lot, and then through the join silane coupling agent KH550, the formation of a surface of carbon nanotubes was enshrouded;Again with poly lactic acid(PLA) as the main body, the PHB as the auxiliary materials, carbon nanotubes in order to strengthen the body, the tried for PLA/PHB/carbon nanotube composite materials by HAAKE.The infrared absorption spectral analysis had the carbon nanotubes treatment; By using scanning electron microscopy (SEM) analysis process of the dispersion of carbon nanotubes and accumulation form; Use a tensile test, impact test, static bending test to study the mechanical properties of composite; By micro burning calorimeter(MCC) study the thermal stability of the composite material performance; Capillary rheometry study the rheological properties of composite material can; Using vicat softening temperature tester(VST) of composite materials were vicat softening temperature.

Through the carbon nanotubes infrared spectral analysis indicates that, after TEOS and silane coupling agent comprehensive treatment in carbon nanotubes surface to the success of a large number of grafted functional group, and the surface coated with effectively attached to the group.

Mechanical properties research indicate that by elastomer PHB later, material of tensile strength, impact s treng th, elongation at break improve, static bending strength decline. Add a small amount of carbon nanotubes after, the tensile strength of the composite, impact strength and bending strength has greatly improved, elongation at break down. But the increasing of the carbon nanotubes components, because this is due to the reunion of carbon nanotubes in and the compound material interface bond drop, impact strength fell.

Include research shows that, PLA to join PHB, in low shear rate, apparent viscosity increases the system; In the higher shearing rate, apparent viscosity of the system of less than pure PLA, explain to join PHB after, the system will be more apparent viscosity shearing rate influence. In the join carbon nanotubes after, apparent viscosity increases the system, and the greater the content of carbon nanotubes, the greater the apparent viscosity.