Shape-memory performance of electrospun thermoplastic polyurethane/polyethylene oxide blend fibrous membranes with diverse morphological structures

The present study aimed at exploring the effect of morphological structure design on shape-memory effect (SME) of thermoplastic polyurethane/polyethylene oxide (TPU/PEO) blend electrospun fibrous membranes (EFMs), that were fabricated by co-spinning, dual-jet spinning, and layer-by-layer spinning, respectively. Tunable shape-memory performances of co-spun EFMs were realized by simply varying the blend ratio of TPU and PEO in individual fiber. By comparison, the sample containing 50 wt% PEO showed the best SME due to the rich blend interface in individual fiber and the sufficient fusion points between fibers, both of which promoted the synergistic effect between two components in optimizing SME. As turning the TPU/PEO co-spun fibers into well-separated TPU and PEO fibers by dual-jet electrospinning, the interaction channels were reduced to only the fusion points between fibers, leading to the simultaneous decrease of shape-fixity and -recovery ratios. After assembling the TPU and PEO fibers into a sandwich-structured structured EFM, the SME was further degraded due to the few diffusion points between fibers located at the layer interface. This work provides a good guidance for developing high-performance shape-memory EFMs.