Studies on the properties of graphene oxide-reinforced starch biocomposites

Glycerol-plasticized pea starch/graphene oxide (PS/GO-n) biocomposite films with different loading levels of graphene oxide (GO) were prepared by solution casting method. The structure, morphologies and properties of biocomposite films were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), Ultraviolet-visible (UV-vis) and tensile tests. The results revealed that hydrogen bonding formed in the biocomposite films, which improved compatibility between GO fillers and starch matrix. The tensile strength (σb) and Young's modulus (E) of starch films containing 2.0 wt% GO increased from 4.56 MPa, 0.11 GPa to 13.79 MPa, 1.05 GPa, respectively, while the elongation at break (ɛb) decreased from 36.06% to 12.11%. The introduction of GO also reduced moisture uptake (Mu) and UV transmittance of starch films. In addition, TGA showed that the thermal stability of biocomposite films was better than that of neat starch film.