A multi-functional chromone-modified polyethylene obtained by metal-free C–H activation

Post-modification of polyolefins by cutting-edge C–H activation has recently emerged as an attractive methodology for the incorporation of precise functionalities, thus expanding their applicability and creating value-added materials. In this report, chromone (CM), the core of naturally occurring molecules possessing manifold biological and pharmacological activities, was incorporated into polyethylene (PE) through the recently developed radical-mediated alkane C–H activation approach. The reaction was conducted in the presence of di-tertbutyl peroxide as the oxidant and a small amount of naphthalene as the solvent or under solvent-free conditions. The produced CM-grafted PEs (CM-PEs) exhibited intriguing antioxidative and fluorescence properties as revealed by thermogravimetric analysis (TGA) and fluorescence microscopy. Moreover, CM-PEs were successfully demonstrated to act as a polymer-bound antioxidant, a fluorescence marker for plastic sorting, and a traceable compatibilizer for the PE/polystyrene blend, revealing that CM-PE is a multi-functional material.