Harnessing nanostructures and fiber architecture: A synergistic leap in shape memory polymer composites

Abstract

This research investigates the synergistic effects of carbon fiber orientation and nanostructure reinforcement across 21 configurations of shape memory polymer composites. It examines uni-directional (UD), bi-directional Twill (BDT), and bi-directional Plain (BDP) fiber architectures, along with varying concentrations of MWCNT and GnP at 0.4%, 0.6%, and 0.8%. The fabrication process involves initially preparing nanostructure-modified epoxy nanocomposites through ultrasonication followed by hand layup techniques to fabricate three-phase shape memory polymer composites. Optimal tensile performance is observed in GnP-modified UD composites at a 0.6 wt% concentration, achieving a tensile strength of 728.32 MPa and a modulus of 71.29 GPa. Furthermore, enhancements in thermomechanical and shape memory properties are noted in GnP-modified BDT composites and are further improved in GnP-modified BDP composite configurations. GnP-modified composites outperform MWCNT ones due to GnP’s sheet structure aligning parallel to the load and its larger surface area, which facilitate enhanced interaction with the matrix. These improvements, supported by FESEM analysis, highlight enhanced interfacial bonding and result in high shape recovery ratios, with all configurations exceeding 90%, despite polymer modification.