Nanotailoring of thermoplastic polyurethane by amine functionalized graphene oxide: Effect of different amine modifier on final properties

Thermo-mechanical properties of amine functionalized graphene oxides filled polyurethane (PU) nanocomposites have been investigated in this work. Graphene oxide (GO) was functionalized with p-phenylenediamine (PPD), hexamethylene diamine (HMD) and liquid NH3 separately to check the interaction with the PU matrix. In-situ solution polymerization technique has been adopted for the preparation of nanocomposites. The functionalization of GO with PPD, HMD, and NH3 was proved by Fourier transform infrared spectroscopy (FTIR), Raman Spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible spectroscopy. Furthermore, grafting of PU onto the functionalized GO surface has been confirmed from the FTIR and TGA analysis, and the filler dispersion is shown in the respective FESEM and TEM micrographs. With the incorporation of just 0.1 wt% amine functionalized GO, thermal and mechanical properties improve significantly, and the surface becomes more hydrophobic compared to GO filled nanocomposites. Maximum improvement in properties was observed with PPD functionalized GO (GO-PPD) filled PU nanocomposites. At 0.1 wt% loading of GO-PPD, tensile strength, and Young's modulus increases by 378% and 145%, respectively. In addition to these, maximum degradation temperature also increases by 13 degrees C, which is more than double compared to 0.1 wt% GO filled nanocomposite. Resilience behavior of PU also improves significantly with the addition of amine functionalized GO.