【作者】 喻光辉；

【导师】 曾繁涤；

【作者基本信息】 华中科技大学 ， 高分子化学与物理， 2005， 硕士

【摘要】 自从上个世纪末纳米技术的出现,纳米材料的独特性能引起人们的广泛关注。把纳米材料与高分子材料复合,制备高性能和功能化的复合材料成为高分子材料领域的热点之一。作为纳米材料领域之一的碳纳米管(CNTs)具有独特的物理性能,是一种具有纳米直径的管状碳纤维,它具有超强的韧性和强度以及优异的导电性能。通过不同的复合方法可制备出增强、导电和电磁屏蔽的优异性能的材料,具有广泛的应用前景。本论文通过不同的方法制备了不同高分子基碳纳米管复合材料,研究了CNTs在基体中分散状况和复合材料的力学、热学和导电性能,并探讨了CNTs对复合材料的结构和性能的影响。借助超声波的作用,CNTs 均匀分散于单体中,然后通过原位聚合的方法制备了聚氨酯/碳纳米管复合材料。通过透射电镜和扫描电镜观察了CNTs 分散状况和材料的结构,然后对材料的力学、热学和电性能进行了研究。结果表明,CNTs 在基体中分散良好,两相间有较好的相容性。材料的力学性能得到提高,在CNTs 的质量含量为2%时达到最好的效果,其中断裂强度提高11.6%,模量提高11.3%,断裂伸长率提高10.4%。同时质量含量为1%的CNTs 使复合材料具有抗静电性能。其后针对该实验存在的问题进行了改进的实验方法。结果表明,借助表面活性剂的作用,CNTs 的分散效果更好,反应进行更加完全,两相间有更好的结合力,力学和电性能也得到更大的提高。最后采用溶液共混的方法制备了高密度聚乙烯(HDPE)/CNTs复合材料。通过电镜观察了材料的形貌,用DSC分析了材料的热性能,同时对复合材料的力学和电性能进行了探讨。结果表明,CNTs在基体中分散良好,由于CNTs的异相成核作用,提高了材料的结晶度,材料由塑性断裂转变为脆性断裂。熔融温度和拉伸强度得到提高,同时,材料具备了抗静电的功能。更多还原

【Abstract】 With the appearance of the nanotechnology in the end of last century ,the particular properties of the nanomaterials have absorbed comprehensive attention. Through combination nanomaterials with polymers, preparing the composite materials which have good synthetic function or special function have become the hotspot in the field of polymer. As one of the nanomaterials, Carbon nanotubes(CNTs) is the most special which has the nano diameter, superior tenacity and conductivity. Trough different methods, we can prepare some composite which have the properties of good mechanical, conductivity and electromagnetic shielding and so on. So the usage of the CNTs has the profound foreground. In this thesis, we adopted the different methods to prepare the different carbon nanotube composites, and mainly studied their mechanical properties, electric properties and thermal properties. Moreover, we discussed how the addition of carbon nanotubes effected the structure and properties of the composite materials. Through the process of ultrasonic, the CNTs were dispersed in the monomer. Then via in-situ polymerization, the polyurethane /CNTs composite was prepared. The disperse configuration of CNTs was studied via SEM and TEM, then we studied the thermal properties, mechanical properties and electric properties. The result showed that the CNTs were dispersed well in the composite, the mechanical property of the composite was best when the content of CNTs was 2%, of which the Peak Stress, Strain At Break and Modulus were enhanced 11.6%, 11.3 %and 10.4% respectively. At the same time, 1% weight of CNTs can make the composite have the ability of antistatic. Then we carried out modified experiment scheme aimed at the high viscosity and binding force of CNTs and PU. The result showed that CNTs were dispersed better and the reaction went on more complete with the help of tween80. As the compatibility of the two phases was boosted ,the mechanical properties and conductivity were increased more. Polyethylene/carbon nanotubes composites were prepared with the method of cross blend in solution. The disperse configuration of CNTs was studied via SEM and the thermal properties was studied, at the same time the tensile and the conductivity were discussed. The result showed that CNTs dispersed in the matrix in nanometer scale and interface bonding was good. As CNTs exerted the function of heterogeneous nucleation, the degree of crystallinity was enhanced that result in the fracture behavior of the polymer altered from plastic to fragile and the melt temperature increased. The addition of carbon nanotubes was benefit to improving mechanical property, at the same time the composite has the ability of antistatic.更多还原