Unique Multifunctional Thermally-Induced Shape Memory Poly(p-dioxanone)-Poly(tetramethylene oxide)glycol Multiblock Copolymers Based on the Synergistic Effect of Two Segments

Biodegradable and biocompatible poly(p-dioxanone)-poly(tetramethylene oxide)glycol (PPDO-PTMEG) multiblock copolymers with excellent shape memory effect and mechanical properties were developed by coupling PPDO-diol and PTMEG-diol with 1,6-hexamethylene diisocyanate (HDI). The influences of chain structure, microphase separating morphology on shape memory effect, and biocompatibility were investigated systematically. The TEM observation of PPDO-PTMEG poly(ether-ester)-polyether exhibited the relationship between characteristic microphase separating morphology and shape memory effect. Interestingly, differential scanning calorimetry (DSC) analysis indicated that T-g,T-PPDO was close to T-c,T-PTMEG, which provided the possibility that the reversible phase combined PTMEG segments and the amorphous phase of PPDO segments. The synergistic effect ensured copolymers owning both high R-f and R-r (96.6% and 92.9% with PTMEG segments only 15% in weight fraction), as well as the mechanical properties when T > T-trans. Moreover, biocompatible evaluation results showed that the cell adhesion and proliferation could be enhanced on copolymers with more PTMEG segments, indicating potential application in minimally invasive surgery.