Enhanced Mechanical Performance of Adgebaepoxyresin‐basedshape Memory Polymer by Introducing Graphene Oxide Via Covalent Linking

Shape memory polymers (SMP) are prepared, via dual thiol-epoxy/thiol-ene reactions, from diglycidyl ether of bisphenol A (DGEBA), a trithiol (TMP), a tetraallyl amine (TAA), and small amounts (0.1-0.5 wt.%) of graphene oxide either pristine (GO) or functionalized with methacrylate groups (GO(M)). The incorporation of GO(M) to the epoxy resin network permits a good load transfer, which is reflected in improved properties such as Young modulus (from 220 to 519 MPa), tensile strength (from 46.3 to 69.2 MPa), Izod impact strength (from 0.051 to 0.42 J/mm), torque (from 0.008 to 0.031 Nm), and glass transition temperature (from 75 to 105 degrees C). Such improvement in properties is attributed to the incorporation of GO(M) via covalent linking, which is a good strategy for improving polymer-particle interaction and particle dispersion. The epoxy-based SMP also show high storage modulus (up to 2.36 GPa) and high deformation capacity, which are reflected in good shape fixity (between 97% and 100%) and thermo-induced shape recovery (between 97% to 99.7%) behaviors in flexion mode tests.