Studies on the secondary modification of SBS modified asphalt by the application of octadecyl amine grafted graphene nanoplatelets as modifier

Modified asphalt prepared via graphene nanoplatelets (GNPs) incorporation to styrene-butadiene-styrene (SBS) possesses enhanced high temperature performance and mechanical properties but the approach suffers from poor compatibility of the components. In this study, octadecyl amine (ODA) was grafted onto the surface of GNPs resulting in ODA-GNPs composite via covalent bonding method. GNPs and ODA-GNPs composites were applied as modifiers to SBS for modified asphalt preparation. Specific amount of ODA-GNPs incorporation improved ductility, softening point and penetration while DSR, MSCR and segregation experiment showed enhancement in viscoelastic, high temperature rutting resistance performance and compatibility of the SBS modified asphalt. Textural characterization of asphalt samples using FT-IR, XRD, SEM and AFM revealed the successful grafting of ODA onto GNPs surface resulting in increased interplanar spacing of GNPs. ODA grafted onto the surface of GNPs enhanced its lipophilicity in asphalt, leading to better particles dispersion. The present methodology using ODA-GNPs composite for the preparation of modified asphalt with enhanced mechanical properties, temperature resistance and viscosity, can be deemed as an efficient approach on industrial level applications.