Reinforcing of phenol formaldehyde resin by graphene oxide and lignin nanohybrids

Utilizing synergetic effects of different fillers was an important strategy to develop high-performance polymer nanocomposites. In this work, novel hybrid nanofillers composed of graphene oxide (GO) and alkali lignin (L) were obtained successfully, and their reinforcing effect of phenol formaldehyde (PF) resin was fully investigated. The structures, morphologies, and properties of the GO-L nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscope, thermal gravimetry analysis, and Raman spectra. Dynamic mechanical analysis results showed that the GO-L–reinforced PF resin is much better than the single added GO and lignin with the same weight ratio. The effect of the filling ratio of GO-L on the storage modulus of PF was also investigated. Results showed that the storage modulus of PF was increased from 2015 MPa to 3675 MPa with the addition of 2 wt% of GO-L (3:7) hybrids