Most of the fillers can significantly improve the elastic modulus
and recovery stress of SMPs. Microfibers are superior to micro- and
nano-sized particles to reinforce SMPs. Rod-shaped clay nanofillers
have better reinforcement effect than spherical nanoparticles as a
result of their high aspect ratios. Fillers which can have chemical
bonding with SMP chains are more effective in improving the shape
memory performance and the mechanical properties of SMPs.
Fillers performing the function of cross-linking agents not only
reinforce the SMP, but also improve the shape memory properties.
Fillers which improve the thermal conductivity of the polymer
matrix [329e331], can have positive effect on the SME of SMPs.
Many researchers also studied the influence of fillers on the thermal
expansion of SMPs. This research is necessary if exact shape
control is required during the thermomechanical process [332e
336]. All research shows that inorganic fillers can more or less
improve the thermal stability of SMPs [17,317,337,338].