Visible‐Light LED Triggered Thiol‐Ene Click Reactions: A Green and High‐Performance Fabrication Strategy for Flame‐Retardant Films

ABSTRACT Thiol‐ene click reactions are renowned for advantages of insensitivity to oxygen and rapid curing rates. Light emitting diode (LED)‐triggered polymerizations, which are characterized by low energy consumption, no solvent pollution and volatile organic compounds (VOC)‐free, are also a well‐known process for the preparation of polymers. However, there is a paucity of literature detailing the synthesis of flame‐retardant films integrating these two unique reactions. In this study, we report the fabrication of flame‐retardant films via visible‐light LED triggered thiol‐ene click reactions. Encouragingly, the flame‐retardant films with significant flame‐retardant properties were successfully prepared even under the low‐intensity visible‐light source and in air. Importantly, the resulting films containing 25% PN‐DOPO (a phosphaphenanthrene oxide based on a bridged DOPO derivative), exhibited an impressive limiting oxygen index (LOI) of 30.8% and achieved the optimal UL‐94 V‐0 level. The proposed strategy not only facilitates a green and efficient method for the preparation of flame‐retardant films but also offers a novel concept for the development of environmentally sustainable flame‐retardant materials in the future, thereby expanding the applications of such films to coal mine fire prevention and thermal protective textiles.