Intrinsically elastic and self-healing luminescent polyisoprene copolymers formed via covalent bonding and hydrogen bonding design

Although development of soft and stretchable materials exhibiting semiconducting functions, such as luminescent or electronic properties, has received growing interest, development of intrinsically self-healing semiconducting materials remains a challenge. In this study, covalent and hydrogen-bonding architectures were used to construct polyisoprene (PI)-based rubber containing luminescent poly[2,7-(9,9-dioctylfluorene)] (PF), and the material exhibited elastic behavior and spontaneous healing. The first demonstration of an engineered hard–soft multiphase, well-dispersed polymer thin film was conducted, wherein the soft phase backbone containing dynamic hydrogen bonds and rubber-like moieties imparted resistance against damage due to repeated stretching, while the hard phase comprising aggregates of rigid PF branches imparted luminescence. Under intense mechanical stress, both the bulk and thin-film states of the crosslinked PF0.16-co-PI0.37-co-PBACO0.47 impressively presented typical elastic performance. Owing to the dynamic nature of the hydrogen bonds within the crosslinked polyisoprene copolymer, the bulk and thin film states exhibited good self-healing and an 83% recovery efficiency following treatment for 24 h at room temperature. This strategy is potentially useful for fabrication of fully flexible electronics with good mechanical properties and many functionalities. Covalent and hydrogen-bonding architectures were designed in polyisoprene (PI)-based rubber containing the conjugated poly[2,7-(9,9-dioctylfluorene)] (PF) to enable elastic and luminescent behavior with spontaneous healing features.