Body Temperature-Triggered Shape-Memory Effect via Toughening Sustainable Poly(propylene carbonate) with Thermoplastic Polyurethane: toward Potential Application of Biomedical Stents

Shape-memory polymeric materials triggered by body temperature were fabricated via toughening sustainable poly(propylene carbonate) (PPC) with thermoplastic polyurethane (TPU). With an addition of TPU through melt blending, the ductility of PPC was dramatically enhanced, leading to the increase of shape recoverability but a deterioration of shape fixity. Remarkably, the blend containing 50 wt % TPU (PT50) presented the optimal shape-memory effect (SME) with balanced shape recovery and shape fixation performances because of the formation of the co-continuous structure promoting the synergy between PPC and TPU. Moreover, the PT50 sample exhibited significant improvement in not only the shape recovery ratio (similar to 95.0% recovery) but also the recovery speed and recovery stress, which enabled it to achieve an excellent SME when applied in practical use. After processed into a spiral-like stent, PT50 still showed a fast response to 37 degrees C, giving an efficient self-expansion within only 20 s. Besides, the blood and cell compatibility testing results revealed the good biocompatibility of PT50, further demonstrating the great potential of this material for development of biomedical stents.