The influence of functionalized MWCNT reinforcement on the thermomechanical properties and morphology of epoxy nanocomposites

The nature of the interphase, often considered the third phase of nanocomposites, has been a central topic in nanocomposites research. In this study, an ionic bonding scheme was employed to graft epoxy-compatible amine terminated linear polypropylene oxide (A-PPO) molecules of different molecular weight to oxidized multi-walled carbon nanotubes (o-MWCNTs), and thereby modify the interphase of MWCNT-epoxy nanocomposites. The amine-cured epoxy systems reinforced with different functionalized MWCNTs demonstrated divergent thermomechanical properties. Fractography revealed distinct fracture behaviour for nanocomposites with long-chain A-PPO modified MWCNTs. The results demonstrate the feasibility of interphase control and performance engineering through the judicious choice of polymer grafts.