Dual stimulus response mechanical properties tunable biodegradable and biocompatible PLCL/PPDO based shape memory composites

The aliphatic polyester poly(L-lactide-co-ε-caprolactone)(PLCL) was synthesized successfully in this research. And a temperature-responsive and water-responsive shape memory composite was prepared by the physical blend of PLCL and poly (p-dioxanone) (PPDO) for the first time. The thermal properties, crystallinity, microstructure, mechanical properties, shape memory behavior, and degradation properties of PLCL/PPDO composites were comprehensively investigated. The results showed that the mechanical properties of the composite could be adjusted with the addition ratio of PPDO. All materials possessed excellent shape memory fixation rates: close to 100%. PPDO improved the shape memory recovery ratio of PLCL without affecting the shape memory fixation ratio of PLCL. PL/PP82 showed the best shape memory recovery ratio at 37°C with 91.34 ± 3.56%. A combination of in situ wide-angle X-ray scattering and tensile modes was used to elucidate the unique mechanism of shape memory in the air for this range of composites. PL/PP82 also exhibited excellent thermal and water-induced shape memory effects in water at 37 °C, with a rapid return to the original state of the composite within 19 s. The introduction of PPDO improved the degradation rate of the composite and regulated the rate of degradation. Additionally, the addition of PPDO significantly enhanced the hydrophilicity of the composites, which promoted proliferative adhesion of osteoblasts to the composite surface. Thus, the temperature and water responsive shape memory composites had great potential in bone tissue engineering applications.