N-doped reduced graphene oxide/waterborne polyurethane composites prepared by in situ chemical reduction of graphene oxide

In this study, N-doped reduced graphene oxide/waterborne polyurethane (NRGO/WPU) composites were prepared by in situ chemical reduction of graphene oxide in an aqueous solution system. The morphology, structure, electrical conductivity, electromagnetic shielding, as well as thermal stability of the NRGO/WPU composites were characterized. The results show that simultaneous chemical reduction and N-doped functionalization of graphene oxide were achieved using diethylenetriamine as a reducing agent and N-doping agent. The introduction of NRGO could endow the WPU with quality electromagnetic interference shielding effectiveness (EMI SE). The composites with 12 wt% NRGO content exhibited the EMI SE of 28.3 dB at 9 GHz. Attributable to the uniform distribution of NRGO in the WPU matrix and its formed network structure, the NRGO/WPU composites had a better electrical conductivity compared with virgin WPU. TG and DTG indicated that the NRGO/WPU composites had a better thermal stability than virgin WPU.