High Mechanical Performance Composite Conductor: Multi-Walled Carbon Nanotube Sheet/Bismaleimide Nanocomposites

• Published in: Advanced functional materials Vol. 19; no. 20; pp. 3219 - 3225
• Main Authors: Cheng, Qunfeng, Bao, Jianwen, Park, JinGyu, Liang, Zhiyong, Zhang, Chuck, Wang, Ben
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 23.10.2009; WILEY‐VCH Verlag
• Subjects: Bismaleimide resin; Carbon nanotubes; Composites; Electrical conductivity; Mechanical properties; Nanotube alignment
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.200900663

Multi‐walled carbon nanotube (MWNT)‐sheet‐reinforced bismaleimide (BMI) resin nanocomposites with high concentrations (∼60 wt%) of aligned MWNTs are successfully fabricated. Applying simple mechanical stretching and prepregging (pre‐resin impregnation) processes on initially randomly dispersed, commercially available sheets of millimeter‐long MWNTs leads to substantial alignment enhancement, good dispersion, and high packing density of nanotubes in the resultant nanocomposites. The tensile strength and Young's modulus of the nanocomposites reaches 2 088 MPa and 169 GPa, respectively, which are very high experimental results and comparable to the state‐of‐the‐art unidirectional IM7 carbon‐fiber‐reinforced composites for high‐performance structural applications. The nanocomposites demonstrate unprecedentedly high electrical conductivity of 5 500 S cm−1 along the alignment direction. Such unique integration of high mechanical properties and electrical conductance opens the door for developing polymeric composite conductors and eventually structural composites with multifunctionalities. New fracture morphology and failure modes due to self‐assembly and spreading of MWNT bundles are also observed. High concentration (∼60wt%) multi‐walled carbon nanotube sheet/bismaleimide composites are fabricated using simple mechanical stretching and prepregging methods, resulting in unprecedentedly high electrical conductivity (5 500 S cm−1) and mechanical properties (strength of 2 088 MPa and modulus of 169 GPa) comparable to those of unidirectional carbon fiber‐reinforced composites for high‐performance structural and multifunctional applications.