High-performance CNT sheet/bismaleimide nanocomposites

Bismaleimide (BMI) resin/carbon nanotube composites are very attractive for high temperature and high conductive applications. Several researchers have reported attempts to reinforce BMI resin with CNTs; however, the resultant mechanical properties were much lower than their predicted values due to several obstacles, such as low CNT loading, poor interfacial bonding, short CNT length and lack of nanotube alignment. This paper reports on our research with carbon nanotube sheets of millimeter-long MWNTs/BMI resin composites that have a high degree of alignment and epoxidation functionalization. The resultant nanocomposites achieved record-high tensile strength of 3,081 MPa and modulus of 350 GPa, far exceeding those of the state-of-the-art unidirectional carbon fiber-reinforced composites. We also explore the structureproperty relationship and new failure mode due to the unique CNT packing structures observed in the resultant nanocomposites.