长纤维增强尼龙6复合材料技术的研究与开发

发布时间：2018-04-16 23:21

本文选题：长纤维 + 尼龙6(PA6)　；参考：《北京化工大学》2015年硕士论文

【摘要】：长纤维增强热塑性复合材料(Long Fiber reinforced Thermoplastics,LFTs)技术近年来取得了快速、稳定的发展,并已成为制备高性能工程材料的重要方法。LFT复合材料综合性能显著优于传统短纤维增热塑性复合材料(Short Fiber reinforced Thermoplastics, SFTs)的主要原因是,LFT技术可以最大程度的保留复合材料中纤维长度,实现增强效率最大化。LFT复合材料不仅表现出优异的力学强度,同时具有生产效率高、可回收性强等特点,在工业领域尤其是汽车行业得到了广泛的应用。本文采用长玻璃纤维(LGF)、长碳纤维(LCF)为增强体、尼龙6(PA6)为基体,通过长纤维熔融浸渍技术制备了两种LFT复合材料并对性能进行表征。主要工作包括如下两部分：1、通过制备LGF/PA6复合材料对LFT技术进行初步探索。研究了LGF含量对于LFT复合材料的力学性能、热变形温度(HDT)的影响。重点对比了LGF/PA6与短玻纤增强尼龙6(SGF/PA6)复合材料的力学性能、纤维残留长度,结果表明,LGF/PA6的增强效果明显高于SGF/PA6,尤其是缺口冲击强度,而前者的纤维残留长度约为后者的6倍,纤维长度的大小是影响二者力学强度的主要原因。LFT粒料扫描电镜(SEM)照片表明LGF在树脂基体中得到了良好的浸渍。2、利用LCF的导电性以及镍粉(Ni)的磁导率,在LFT技术的基础上制备了力学性能优异同时电磁屏蔽功能良好的LCF/Ni/PA6复合材料。对于LCF/Ni/PA6复合材料力学性能的研究表明随着LCF含量的增加力学性能大幅提高,而镍粉的加入并没有对力学性能产生较大的影响。电导率测试表明复合材料具有良好的体积电导率并且在较低的LCF含量下可以形成逾渗网络；介电性能测试表明复合材料具有较高的介电损耗,对电磁波能量具有良好的吸收损耗作用。通过矢量网络分析仪测试了电磁屏蔽性能,并对屏蔽机理进行研究,结果表明LCF/Ni/PA6复合材料具有较高的屏蔽效能并且主要通过吸收的方式实现电磁波的屏蔽,体现了LCF、镍粉对于电磁波良好吸收作用。另外,TGA测试研究复合材料热稳定性发现LCF、镍粉的加入对于热稳定性具有一定提高作用；通过SEM观察了复合材料的微观结构,表明LCF与基体PA6间具有良好的界面性能。
[Abstract]:Long fiber reinforced thermoplastic composites (LFTs) have developed rapidly and steadily in recent years.The main reason why short Fiber reinforced thermoplastics (SFTs) is superior to the traditional short fiber reinforced thermoplastic composites is that LFTs can keep the fiber length in the composites to the maximum extent.To realize the maximum reinforcement efficiency. LFT composites not only exhibit excellent mechanical strength, but also have the characteristics of high production efficiency and high recoverability. LFT composites have been widely used in industrial field, especially in automobile industry.In this paper, two kinds of LFT composites were prepared and their properties were characterized by long fiber melt impregnation technique using long glass fiber (LCF) and long carbon fiber (CF) as reinforcements and nylon 6 (PA6) as matrix.The main work includes the following two parts: 1: 1. The LFT technology is preliminarily explored by the preparation of LGF/PA6 composites.The effects of LGF content on the mechanical properties and thermal deformation temperature of LFT composites were studied.The mechanical properties and fiber residual length of LGF/PA6 and short glass fiber reinforced nylon 6 / SGF / PA6 composites were compared. The results showed that the reinforcement effect of LGF- / PA6 was significantly higher than that of SGF- / PA6, especially the notched impact strength, and the fiber residual length of the former was about 6 times of that of the latter.The size of the fiber length is the main reason that affects the mechanical strength of the two materials. The SEM photos show that LGF is well impregnated in the resin matrix. The conductivity of LCF and the permeability of Ni) are used.On the basis of LFT technology, LCF/Ni/PA6 composites with excellent mechanical properties and good electromagnetic shielding function were prepared.The mechanical properties of LCF/Ni/PA6 composites were studied. The results showed that the mechanical properties of LCF/Ni/PA6 composites were greatly improved with the increase of LCF content, but the addition of nickel powder had no significant effect on the mechanical properties.The conductivity test shows that the composite has good volume conductivity and can form percolation network at low LCF content, and the dielectric property test shows that the composite has high dielectric loss.It has good absorption loss to electromagnetic wave energy.The electromagnetic shielding performance is tested by vector network analyzer, and the shielding mechanism is studied. The results show that LCF/Ni/PA6 composite has high shielding efficiency and the electromagnetic wave shielding is mainly achieved by absorbing.The effect of LCF and nickel powder on electromagnetic wave absorption is demonstrated.In addition, the thermal stability of the composite was studied by TGA. It was found that LCF and the addition of nickel powder could improve the thermal stability, and the microstructure of the composite was observed by SEM, which showed that the interfacial properties between LCF and matrix PA6 were good.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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