A shape memory polymer with improved shape recovery

Thermally actuated shape memory polymers (SMPs) interest, both academically and industrially, due to their ability to memorize a permanent shape that is set during processing and a temporary shape that is later programmed by manipulation above a critical temperature, either T_g or T _m. However, the thermal triggering process for SMPs is usually retarded compared to that of shape memory alloys, because the thermal conductivity of polymers is much lower (<0.30 W/m.K). In the present study, we incorporated a highly thermal conducting filler into a shape memory matrix to increase its thermal conductivity and therefore, shorten the heat transfer progress. A mathematical was worked out that quantitatively relates the material's thermal conductivity with the heat transfer time, τ, also defined as a shape memory induction time. The model fit nicely with our experimental data. In addition, mechanical reinforcement was observed with the addition of this rigid thermal conducting filler.