Synthesis and characterization of graphene/polyurethane

Graphene oxide was synthesized by the improved Hummers method, treated with isocyanate, and used for preparation of polyurethane (PU) hybrid films, which was synthesized with tolylene diisocyanate (TDI) and polyethylene glycol-600 (PEG-600). The synthesized materials were characterized by Raman spectra, Fourier transform infrared spectrometer, X-ray diffractomer and scanning electron microscope. The results show that the isocyanate could successfully react with the hydroxyl and/or carboxyl groups of graphene oxide. The isocyanate-treated graphene oxide (iGO) is of more irregularity and has higher monolithic rate than graphite and graphene oxide. The water contact angle and the equilibrium moisture content of the PU film are 126° and 40%, respectively. When 1.5% iGO is used for the iGO-PU hybrid films, its water contact angle and the equilibrium moisture content decrease to 80° and 30%, respectively. After 7d of immersion in dilute hydrochloric acid, the film mass loss of this iGO-PU hybrid film is only 2.5%.