CNT buckypaper/thermoplastic polyurethane composites with enhanced stiffness, strength and toughness

Carbon nanotube buckypaper/thermoplastic polyurethane elastomer composites were successfully fabricated. At certain polyurethane contents, the composites exhibited simultaneous improvements in stiffness (up to 6 GPa), strength (up to 120 MPa), ductility (up to 30%) and toughness (up to 36 MJ/m3). The measured elastic modulus of the composites could be predicted by Mori-Tanaka model. The possible reinforcing mechanisms were discussed by Raman spectroscopy and SEM fractography. The results revealed that ductile polymers are very promising matrix in balancing the key mechanical properties of buckypaper, which are beyond the commonly used brittle thermosettings, e.g. epoxy resin.