Mutifunctional Electrospun Nonwoven Mats with Two-Way Shape Memory Behavior Prepared from Sol-Gel Crosslinked Poly(ε-Caprolactone)

Nonwoven fibrous mats based on semicrystalline networks are prepared starting from poly(epsilon-caprolactone) and properly combining electrospinning and sol-gel reactions. The mats are obtained as continuous, randomly oriented micrometric fibers with different network densities. The systems are subjected to thermomechanical cycles to investigate their one-way and two-way shape memory behavior. One-way tests aim at exploring the effects of the deformation temperature on the materials response, with particular interest to the less investigated cold-working conditions (i.e., deformation temperature below T-m). The materials display two-way shape memory capabilities (i.e., the ability to change between two distinguished shapes upon heating and cooling under a fixed nonzero stress) and the effect of the applied stress is explored. The shape memory characterization is accompanied by an ex situ SEM analysis, to describe the concurrent microstructural evolution during the macroscopic shape variation, and by the assessment of their biocompatibility, to explore the suitability of the nonwovens for biomedical applications.