Light responsive self-healable carbon nanotube/polyurethane smart networks with precisely remote-controlled shape-changing properties

Smart materials can dynamically react to environmental stimuli and thus change at the micro or macro scale. However, when exposed to harsh conditions, damage can occur to them to varying degrees, thus affecting their performance and service life. In this study, a recyclable shape memory polyurethane material with self-healing properties was prepared using polycaprolactone (PCL) and polytetrahydrofuran diol (PTMG) as raw materials and isofuranone diisocyanate (IPDI) as a cross-linking agent. Dynamic cross-linking networks are constructed by introducing reversible disulfide bonds to enhance the self-healing and recyclable properties of the materials. Hydroxylated multiwalled carbon nanotubes (MWCNTs-OH), as photothermal particles, impart a remote response ability to the material, making the material temperature variable under near-infrared radiation (NIR). The shape memory recovery of CNT-PCL-PTMG can be triggered remotely and precisely controlled the irradiated NIR area. The results of tensile tests, scanning electron microscopy (SEM) and optical microscopy (OM) show that 3%CNT-5PCL-5PTMG can achieve efficient and rapid self-healing. Additionally, the synergistic effect of transesterification and the dynamic exchange of disulfide bonds gives materials reprocessability for recycling use. The material is promising as an alternative material for soft robotics and smart sensors.