Light-induced shape-memory polyurethane composite film containing copper sulfide nanoparticles and modified cellulose nanocrystals.

Light-induced shape-memory polymer (LSMP) materials have advantages of remote control and precise stimulation under suitable photoactive factors. The excellent performance, stability, and low cost are significant for LSMP materials. Herein, a novel stable and cheap LSMP was prepared with polyurethane (PU) and copper sulfide nanoparticles (CuS NPs) supported on modified cellulose nanocrystals (MCNC) (CuS NPs@MCNC). For the photosensitivity, CuS NPs were formed and assembled on MCNC without other additives. These prepared LSMP films exhibited good light-induced shape memory, which was ascribed to the highly photothermal effect of CuS NPs. We found that the shape recovery ratio was 97.4 % when the PU nanocomposite film containing 0.2 wt.% CuS NPs@MCNC was irradiated by near-infrared (NIR) for 21 s. The ratio was still over 85.7 % after five times of repeat test. These LSMPs contained CuS NPs@MCNC have potential to be applied as a prospective material for medical devices and new packaging.