Chemical functionalization of graphene oxide for improving mechanical and thermal properties of polyurethane composites
2015-11-16T11:31:07Z (GMT) by
Graphene oxide (GO) was chemically functionalized to manufacture polyurethane (PU) composites with improved mechanical and thermal properties. In order to achieve a well exfoliated and stable GO suspension in organic solvent, 4, 4′- methylenebis(phenyl isocyanate) and polycaprolactone diol – two monomers used to synthesize polyurethane – were employed to functionalize GO sequentially. The obtained functionalized GO (FGO) could form homogeneous dispersions in DMF solvent and the PU matrix, as well as provide a good compatibility with the latter. The most efficient improvement in mechanical properties was achieved when 0.4 wt% FGO was added into the PU matrix, corresponding to increases in the tensile stress, elongation at break and toughness by 34.2%, 27.6% and 64.5%, respectively (compared with those of PU). Regarding the thermal stability, FGO/PU 1 wt% showed the largest enhancement, with T2% and T50% 16 °C and 21 °C higher than those for PU, respectively. A significant improvement in both mechanical properties and thermal stability of FGO/PU composites should be attributed to homogeneous dispersion of FGO in the PU matrix and strong interfacial interaction between them.