Preparation and characterisation of PCL shape-memory films via photo-crosslinking

A facile and ecologically friendly method to prepare shape-memory Poly(epsilon-caprolactone) (PCL) films via Ultraviolet (UV) irradiation is described in this work. Benzophenone (BP), as a photoinitiator, was melt-blended with PCL particles directly and then melt-pressed into films. Afterward, a series of shape-memory films were obtained by UV (at around lambda=365 nm) irradiation crosslinking. A sequence study and comparison on the properties changes caused by the effect of irradiation temperature was carried out and it turns out that the gel fraction, shape-memory properties and tensile properties of the PCL films, which were photo-crosslinked at 55 degrees C, were significantly higher than that at 25 degrees C. The effect of photoinitiator contents and irradiation time on gel fraction, shape memory properties and tensile properties was also studied. It is considered that UV irradiation is an efficient method to prepare PCL shape-memory films.