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Journal of Nanomaterials
Volume 2008, Article ID 786405, 15 pages
Research Article

Morphology and Properties of Aminosilane Grafted MWCNT/Polyimide Nanocomposites

1Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30043, Taiwan
2Department of Industrial Safety and Health, Hung Kuang University, Salu, Taichung 443, Taiwan

Received 2 April 2007; Revised 2 September 2007; Accepted 4 October 2007

Academic Editor: Jun Lou

Copyright © 2008 Siu-Ming Yuen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This investigation presents a novel method for modifying multiwalled carbon nanotubes (MWCNTs). The morphology, electrical resistivity, and percolation threshold of MWCNT/Polyimide nanocomposites were studied. Acid-modified MWCNTs reacted with (3-aminopropyl)triethoxysilane by ionic bonding, and were then mixed with polyamic acid via imidization. TEM microphotographs reveal that silane-grafted MWCNTs were connected to each other. The electrical resistivity of silane-grafted MWCNT/polyimide decreased substantially below than that of acid-treated MWCNTs when the silane-modified MWCNT content was lower than 2.4 wt%. The percolation threshold of the MWCNT/polyimide composites is 1.0 wt% for silane-modified MWCNT and exceeds 7.0 wt% for acid-modified MWCNT. The acid-modified MWCNT/polyimide composites possess slightly higher glass transition temperatures than that of pure polyimide. The glass transition temperature of the polyimide increased significantly with silane-modified MWCNT content. Tensile properties of the polyimide have been improved with the MWCNTs content.