Fig. 4
From: High enthalpy storage thermoset network with giant stress and energy output in rubbery state
The multiple energy well model for amorphous thermoset shape memory polymers. a Programming. During programming at temperature above the glass transition zone, the network climbs up an energy hill with local energy well (or dip) (blue line) for local, meta-stale states. At the end of programming (after cooling and unloading), a deep energy well (dashed green line) is formed and thus the network is in a locked, non-equilibrium state. b Recovery. Energy input, such as heating, is needed to drive the cold energy well (dashed green line) back to the hot energy well (solid blue line) and help the CSBs (red circles) jump out of the final energy well, roll down the energy hill, and achieve shape recovery without external constraint, or stress recovery with external constraint
