Shape-memory capability of copolyetheresterurethane microparticles prepared via electrospraying

Multifunctional thermo-responsive and degradable microparticles exhibiting a shape-memory effect (SME) have attracted widespread interest in biomedicine as switchable delivery vehicles or microactuators. In this work almost spherical solid microparticles with an average diameter of 3.9±0.9μm are prepared via electrospraying of a copolyetheresterurethane named PDC, which is composed of crystallizable oligo(p-dioxanone) (OPDO) hard and oligo(ε-caprolactone) (OCL) switching segments. The PDC microparticles are programmed via compression at different pressures and their shape-memory capability is explored by off-line and online heating experiments. When a low programming pressure of 0.2MPa is applied a pronounced thermally-induced shape-memory effect is achieved with a shape recovery ratio about 80%, while a high programming pressure of 100MPa resulted in a weak shape-memory performance. Finally, it is demonstrated that an array of PDC microparticles deposited on a polypropylene (PP) substrate can be successfully programmed into a smart temporary film, which disintegrates upon heating to 60°C. Copolyetheresterurethane microparticles with a diameter of 3.9±0.9μm are prepared via electrospraying. A pronounced thermally-induced shape-memory effect, characterized by a shape recovery ratio of 80%, was achieved by applying low programming pressures (programmed particles size: 5.1μm). By applying of high programming pressure the microparticles were transformed into a smart temporary film, which disintegrates upon heating to 60°C.