Preparation and properties of aminated graphene fiber incorporated modified asphalt

Abstract The inert nature of polyacrylonitrile (PAN) fiber limits the development of fiber asphalt pavement, which can however be tackled by modifying PAN. In this paper, PAN was modified via self-polymerization of dopamine and covalent grafting of aminated graphene, which were in turn used to prepare three kinds of modified asphalt. Dynamic shear rheometer (DSR) tests showed that the aminated graphene modified fiber based asphalt had better viscoelasticity and resistance to permanent deformation than the pristine fiber added asphalt. 3% NH2-GNPs/D-PAN modified asphalt exhibited about 8% higher G* than 3% PAN modified asphalt at a fixed shear frequency. The aminated graphene modified asphalt exhibited enhanced hydrophobicity, adhesion work and water resistance (increased by 14%) than unmodified PAN fiber added asphalt as determined via contact angle measurement. Trabecular bending test and water-immersed Marshall stability test showed that NH2-GNPs/D-PAN incorporated modified asphalt mixture realized the best cracking resistance at low temperature and water damage resistance, which is consistent with the result of DSR and contact angle tests. FT-IR characterization confirmed the successful grafting of amino group onto graphene oxide and that graphite oxide was reduced to graphene. The fiber structure and successful grafting of aminated graphene onto the fiber surface in the PAN modified asphalt was further characterized and confirmed by SEM and AFM.