Largely Improved Mechanical Properties of Polyurethane Nanocomposites via In Situ Polymerization with Low Loading of Graphene Oxide

Polyurethane nanocomposites were prepared and reinforced by graphene oxide (GO) via in situ polymerization. A two-step solvent-replacement process was used to perfectly disperse GO in the PU nanocomposites. The composites exhibited significant improvement in mechanical properties. With only a small amount (0.02 wt%) of GO, the tensile strength showed an increment of 60%. The interfacial interaction between GO and the polymer matrix was deeply investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy, and thermogravimetric analysis. The results showed that the thickness and thermal stability of the polymer-grafted-GO increased obviously. The extreme improvement of the mechanical properties is attributed to the excellent dispersion of GO in the matrix and the strong interfacial interaction. In addition, the resiliency of the PU-GO nanocomposites is still outstanding.