Characterization of shape memory behaviour of CTBN-epoxy resin system

Novel epoxy based shape memory polymers (SMPs) were prepared by blending bifunctional epoxy resin with varying content (0, 5, 10 and 15 wt %) of Carboxyl-Terminated Butadiene Acrylonitrile (CTBN) rubber and cured with a cyclo-aliphatic amine hardener. The epoxy/CTBN blends were chemically characterized by epoxy content and gel time measurements. Neat resin castings were prepared for conducting shape memory tests. The glass transition temperature (Tg) of the test sample was measured in order to fix the deformation temperature (Ttrans). Shape memory (SM) cyclic tests were conducted on both unmodified and CTBN modified epoxy samples in order to comparatively assess their SM behavior. Compared to unmodified epoxy SMPs, the CTBN modified epoxy SMPs exhibited a significant increase in the number of SM cycles, which is attributed to the toughening effect of the CTBN phase.