【作者】 王建国；

【导师】 方征平；

【作者基本信息】 浙江大学 ， 高分子化学与物理， 2006， 博士

【摘要】 关于环氧树脂/碳纳米管复合材料的研究虽然取得了一些进展,但是一些最基本的问题目前并没有真正得到解决。目前采用的分散方法虽然在一定程度上提高了碳纳米管在环氧树脂中的分散程度,但这些方法还不能做到碳纳米管的充分分散,所以寻找合适的方法使得碳纳米管以纳米尺度充分分散在环氧树脂中,仍然是制备高性能碳纳米管/环氧树脂复合材料的首要问题。 本文采用胺功能化的方法处理碳纳米管,考察了胺功能化对碳纳米管在树脂中分散性及得到的复合材料性能的影响。 采用不同的强酸体系和处理条件对碳纳米管进行处理,考察了不同的酸处理体系及条件对碳纳米管结构和化学性质的影响。结果表明,采用硝酸和硫酸的混合酸,在温和条件下处理碳纳米管,可以在不损害碳纳米管基本结构的基础上,在碳纳米管表面产生大量羧基。 采用酰氯化后胺取代路线在碳纳米管表面接枝胺功能基,研究了产物的结构。结果表明,采用酰氯化后胺取代路线可以成功在碳纳米管表面接枝长度不同的多种胺功能基,接枝三乙烯四胺不但把碳纳米管的惰性表面变成极性表面,还可以扩大碳纳米管的管间隙,使碳纳米管的整体状态保持疏松,有利于碳纳米管在聚合物基体中的分散。 碳纳米管环氧树脂的固化行为对其固化物的物理及力学性能有重要的影响。用DSC法研究了加入胺功能化碳纳米管的固化动力学,结果表明,胺功能化碳纳米管的加入降低了环氧树脂固化反应的活化能,且加入胺功能化碳纳米管的环氧树脂固化反应程度高于加入未胺功能化碳纳米管的环氧树脂的固化反应程度。 采用超声波分散的方法制备了碳纳米管/环氧树脂复合材料,并分析了不同碳纳米管对环氧树脂性能的影响。结果表明,胺功能化碳纳米管与环氧树脂有更好的相容性,更易于在环氧树脂中分散,并较大地提高了环氧树脂的强度、韧性、玻璃化转变温度及热分解温度。 研究了多壁碳纳米管对环氧树脂光透过性的影响,并比较了未胺功能化碳纳米管与胺功能化碳纳米管的不同作用,评价了胺功能化碳纳米管/环氧树脂复合材料用做光电器件包装材料的可能。胺功能化可以促进碳纳米管在环氧树脂中的更多还原

【Abstract】 Though some progress on fabricating carbon nanotubes (CNTs)/epoxy composites have been achieved during the past few years, several principle problems have not been got over by now. Those methods recently used to disperse CNTs in polymer matrix cannot disperse CNTs in polymer matrix absolutely uniformly. Consequently, exploring other effective dispersing method remains one of the key problems for fabricating high performance CNTs/polymer composites.In this study, the amino-functionalized multi-walled carbon nanotubes (MWNTs) were produced, and the effects of amino-functionalization on the dispersion of MWNTs in epoxy resin and the properties of the composites were studied.Different acid system and reaction conditions were used to treat MWNTs. The effect of these acid systems on the structure and the chemical nature of the MWNTs were studied. Results showed that by treating the MWNTs with a mixture of sulfuric acid and nitric acid, under relatively gentle reaction condition, could produce a great amount of carboxyl groups on the surface of MWNTs, while bringing no great damage to the MWNTs.By the acid-thionyl route used in this study, triethylene-tetramine (TETA) groups were grafted onto the surface of MWNTs successfully. Results showed that amino-functionalization could not only change the inert surface of MWNTs into active surface, but also enlarge the interspaces in the MWNTs network, which was found helpful to the dispersion of MWNTs in epoxy resin.The effect of amino-functionalized MWNTs on the curing behavior of epoxy/ triethanolamine (TTA) system was investigated using differential scanning calorimetry (DSC). Since the TETA grafted on the amino-functionalized MWNTs could act as curing agent and the produced tertiary amine could act as anionic catalysts for the curing reaction of epoxy/TTA system, the curing activation energy of the epoxy/TTA system was decreased by the addition of amino-functionalized MWNTs. The curing heat of epoxy/TTA/amino-functionalized MWNTs (weight ratio of 1/0.1/0.01) system was higher than epoxy/TTA (weight ratio of 1/0.1) system,while the curing heat of epoxy/TTA/unfunctionalized MWNTs (weight ratio of 1/0.1/0.01) was lower than epoxy/TTA (weight ratio of 1/0.1) system. The addition of the amino-functionalized MWNTs increased the curing degree of the epoxy matrix.MWNTs/epoxy resin composites were fabricated using ultra-sonication method. The effect of amino-functionalized MWNTs on the properties of the epoxy resin was studied. It was found that the amino-functionalized MWNTs were easier to be dispersed and could improve the strength, toughness, glass transition temperature and initial decomposing temperature of the epoxy resin.The effect of amino-functionalized MWNTs on the light transmittancy of epoxy was studied and compared with that of unfunctionalized MWNTs. The application possibility of amino-functionalized MWNTs/epoxy resin composites as packing materials for optoelectronic devices was also evaluated solely in term of light transmittance of the composites. Because amino-functionalization could improve the dispersion of MWNTs in epoxy resin, the amino-functionalized MWNTs/epoxy composites still hold a relative high light transmittancy even the refractive index difference between MWNTs and epoxy resin exceeding 0.1.Two types of MWNTs, with different structure and morphology, were used to fabricate epoxy matrix composites. Mechanical, thermal and TEM measurements were performed to evaluate the different influence of the structure and morphology of MWNTs on the mechanical and thermal properties of MWNTs/epoxy composites. Results showed that the different structure and morphology of MWNTs brought great difference to the mechanical and thermal properties of the obtained MWNTs/epoxy resin composites, and amino-functionalization was found helpful in improving the dispersion of the MWNTs in epoxy resin and thus in fabricating MWNTs/epoxy resin composites with improved mechanical and thermal properties.更多还原