Preparation and properties of functional modification reduced graphene oxide-carbon nanotubes/thermoplastic polyurethane composite films

In order to improve the barrier and antistatic properties of thermoplastic polyurethane (TPU), original carbon nanotubes (CNTs) were added into functional modification reduced graphene oxide (FRGO), and hybrid particles FRGO-CNTs which were uniformly dispersed in N, N-dimethylformamide (DMF) were prepared by non-covalent modification firstly. Then, FRGO-CNTs/TPU composite films were fabricated by solution coating method on the coating machine. Finally, the structures and properties of FRGO-CNTs/TPU composite films were characterized by FTIR, XRD, XPS, FE-SEM, TG, oxygen transmission rate tester, high resistance meter and universal testing machine. The results demonstrate that FRGO and CNTs produce synergistic effect through π-π conjugation, and the prepared FRGO-CNTs show good compatibility with TPU matrix. When FRGO-CNTs content (using TPU as reference) is 2.0wt%, the thermal decomposition temperature of composite film increases by 49℃, and the oxygen transmission rate decreases by 53.7%. The FRGO with large specific surface area and the CNTs with high length to diameter ratio can build the conductive network in TPU matrix. When FRGO-CNTs content is only 0.8wt%, the volume resistivity of FRGO-CNTs/TPU composite film declines by as much as 7 orders of magnitude. Meanwhile, with the FRGO-CNTs content increasing, the tensile strength and elongation at break of composite films both rise at first and then go down.