探討改質奈米碳管應用於聚醯亞胺/多壁奈米碳管奈米複合材料

Characterization on Modified Multi-wall Carbon Nanotube for Synthesis Polyimide/MWNT Nanocomposites

周上智(Shang-Chih Chou)

指導教授 ： 程耀毅

國立臺北科技大學/工程學院/工程科技研究所/博士(2011年)

https://doi.org/10.6841/NTUT.2011.00525

摘要

奈米碳管具有極優異的導電性、機械及熱性質，是一個具有相當高潛力的奈米添加材料，近年來被廣泛的應用於高分子複合材料上，但由於奈米碳管與高分子基材間的介面相容性不佳，易導致奈米碳管聚集成束而無法發揮其預期效果，因此在應用面上我們必須要奈米碳管表面進行改質。在本研究中我們將探討各種表面改質多壁奈米碳管的方法，在奈米碳管表面鍵結上具有極性的官能基，藉以改善奈米碳管與高分子基材間的相容性。本實驗中我們利用熱純化處理、超音波震盪、化學處理如硫酸/硝酸 (體積比3：1) 混酸溶液或是硝酸溶液並與含胺基的小分子化學鍵結等步驟，可以有效的去除非結晶碳 (amorphous carbon) 並在奈米碳管表面界鍵結上具極性的官能基的小分子。將這些已改質的奈米碳管均勻分散於聚醯亞胺基材中，藉由奈米碳管的高長徑比可在聚醯亞胺奈基材中形成網狀分布的結構，有效的提升聚醯亞胺多壁奈米碳管複合材料的導電度，網狀結構也同時限制了聚醯亞胺分子間的運動，進一步的提升其的熱穩定性及機械性質。

關鍵字

聚醯亞胺 ； 奈米碳管 ； 表面改質 ； 奈米複合材料

並列摘要

Carbon Nanotubes (CNTs) with excellent electrical conductivity, mechanical and thermal properties are potential useful as nano-reinforcements in polymer composite which has attracted much attention recently. The lack of interfacial interactions between CNTs and polymer matrix causes facile aggregation of CNTs, therefore, it is necessary to modify CNT to form a polar functional group on the tube surface to enhance the compatibility within a polymer matrix. In this work, we study the various surface modifications of multi-walled carbon nanotubes (MWNT), various methods including thermal purification, ultra-sonication, acid-treatment processes by H2SO4/HNO3 (3:1 by volume) mixture or HNO3, and treatment of amino functional molecules. Thermal purification successfully removes the impurities on CNT surface such as amorphous carbon, and surface modification effectively form polar functional molecules on the tube surface. Homogenous dispersion of polyimide (PI) nanocomposites with various ratios of these modified MWNT was fabricated. Dues to the high aspect ratio of CNT, the formation of a network structure between PI and modified MWNT significantly improves electrical conductivity and also reduces the mobility of PI molecules, thereby increasing its thermal and mechanical properties.

並列關鍵字

Polyimide ； Carbon nanotubes ； Surface modification ； Nanocomposite

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