Shape memory epoxy resin and its composite with good shape memory performance and high mechanical strength

Shape memory polymer composites (SMPC) can find their use as deployable structure devices for aerospace applications due to lightweight, low cost, durable, and functionality. In this work, a binary shape memory epoxy resin (SMEP) system was designed using hydrogenated bisphenol A-type epoxy resin (AL-3040) and diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate epoxy resin (TDE-86). Further, the binary resin system was applied as prepreg for carbon fiber reinforced shape memory composite with vacuum bag degassing molding process. It is found that the glass transition temperature (T-g), tensile strength and Young's modulus of SMEPs were notably increased with increasing TDE-86 content, whereas the impact strength was decreased. The SMEP exhibited good shape memory performance with a shape fixity ratio > 97.1% and a shape recovery ratio > 98.4% after 30 cycles. The whole shape recovery process of SMEP can be completed within 45 s. Compared to neat SMEP, the SMPC showed excellent mechanical properties at both ambient temperature and low temperature. The tensile strength and tensile modulus of SMPC at ambient temporary were as high as 626 MPa and 38 GPa, which were 10 times and 30 times higher than that of SMEP, respectively. Furthermore, the shape memory tests showed that the shape fixity ratio and the recovery ratio of SMPC were both over 95% after 30 cycles. With a higher recovery force provided by carbon fibers, the shape memory process was shortened to 29 s. It seems that the SMPC in this work is quite promising for aerospace applications, such as hinges, deployable panels, and morphing wings.