【作者】 迟雪；

【导师】 杨春秋； 阮诗伦；

【作者基本信息】 大连理工大学 ， 固体力学， 2012， 硕士

【摘要】 碳纳米管因其完美的结构和优异的力学、电学等性能被认为是复合材料的理想填充才料,碳纳米管增强复合材料的研究是纳米材料研究中的热点问题,而由于碳纳米管在基体中的分散和其与基体的界面结合力的问题始终没有得到彻底的解决,目前碳纳米管的增强效率仍然很低,碳纳米管增强复合材料的实验数据与理论数据仍存在一定的差距。一般而言,为了能够得到具有良好导电性能的复合材料需要增加导电填充材料的含量,而添加导电填充材料的同时会在一定程度上削弱材料的力学性能。也就是说,复合材料的高强度与高导电性能一般是不可兼得的。因此,如何在保证力学强度要求的前提下提高材料的导电性能已成为一大难题。为此,研究人员正在尝试采用不同的方法对传统材料进行改性。本文通过熔融共混法分别制备了碳纳米管增强尼龙6复合纤维和羧基化碳纳米管增强尼龙6复合材料纤维,在碳纳米管增强力学性能方面,通过实验系统地测定了复合材料的力学性质与变形行为,研究发现,在未修饰碳纳米管增强尼龙6复合纤维中,拉伸强度在碳纳米管含量为1wt%时达到峰值,比纯尼龙6提高了23.3%,模量则不断提高；在羧基化碳纳米管增强尼龙6复合纤维中,拉伸强度有显著的提高,在碳纳米管含量为1wt%时提高了49.8%；复合材料的在碳纳米管增强电学性能方面,对复合材料纤维的电阻率进行了系统测定,观察复合材料的导电渗流现象,同时分析了复合材料纤维的导电机理。更多还原

【Abstract】 It is well known that carbon nanotubes(CNTs) are considered as ideal fillers in polymer composites due to their perfect structure and excellent mechanical and electrical properties. The research on the CNT reinforced composites is a hot issue in the field of nanomaterials. The efficiency of reinforcement of CNT is still very low and the gap of material properties between the experimental data and theoretical estimation still exists, which may attribute to the bad dispersion of CNTs in the matrix material and the low interfacial strength between CNTs and the matrix material. In general, there is a critical volume concentration of CNTs beyond which the dispersion of CNTs will be bad and the mechanical properties of composites will decrease, but the conductivity will increase with the concentration of CNTs. In order to get a conductive of CNT/polymer composites, it is necessary to add more CNTs in the composites until to a critical concentration of CNTs called percolation. That is, high strength and high conductivity of the composites cannot be obtained at the same time. Therefore, how to improve the electric performance of the composites under the precondition of guaranteeing the mechanical strength has become a interesting problem. Lots of researchers are engaged in this issue and try to obtain this kind of multifunctional composites.In this thesis, the CNT reinforced polyamide6composite fibers with different concentrations of CNTs were prepared by melting injection. At first, the mechanical properties and deformation behavior of the composites were characterized by tensile testing. It is found that the mechanical properties of the polyamide6material increase by different degree. The tensile strength of the MWCNT/PA6increases23.3%with1wt%CNT loading. And the Elastic modulus increases gradually. The tensile strength of composite fiber increases49.8%with1wt%MWCNT-COOH loading. On the other hand, the electrical properties were also characterized by experimental. The phenomenons of conductive percolation were observed and conductive mechanisms of the composite fiber were discussed at the same time.更多还原