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

Multi-walled carbon nanotube (MWNT)-sheet-reinforced bismaleimide (BMI) resin nanocomposites with high concentrations (similar to 60wt%) 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 2 098 M Pa and 169CPa, respectively, which are very high experimental results and comparable to the state-of-the-art unidirectional IM7 carbon-fiber-reinforced 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.