High-Performance and Biobased Polyamide/Functionalized Graphene Oxide Nanocomposites through In Situ Polymerization for Engineering Applications

In this study, biobased polyamide/functionalized graphene oxide (PA-FGO) nanocomposite is developed using sustainable resources. Renewable PA is synthesized via polycondensation of hexamethylenediamine (HMDA) and biobased tetradecanedioic acid. Furthermore, GO is functionalized with HMDA to improve its compatibility with biobased PA and in situ polymerization is employed to obtain homogeneous PA-FGO nanocomposites. Compatibility improvement provides simultaneous increases in the tensile strength, storage modulus, and conductivity of PA by adding only 2 wt% FGO (PA-FGO2). The tensile strength and storage modulus of PA-FGO2 nanocomposite are enhanced dramatically by ≈50% and 30%, respectively, and the electrical conductivity reached 3.80 × 10^–3 S m⁻¹. In addition, rheology testing confirms a shear-thinning trend for all samples as well as a significant enhancement in the storage modulus upon increasing the FGO content due to a rigid network formation and strong polymer-filler interactions. All these improvements strongly support the excellent compatibility and enhanced interfacial interactions between organic–inorganic phases resulting from GO surface functionalization. It is expected that the biobased PA-FGO nanocomposites with remarkable thermomechanical properties developed here can be used to design high-performance structures for demanded engineering applications.