A Universal Strategy for Producing Fluorescent Polymers Based on Designer Hyperbranched Polyethylene Ternary Copolymers

We herein demonstrate a universal strategy for producing fluorescent polymers (FPs) from conventional resins by adding designer hyperbranched polyethylene (HBPE) copolymers based on the aggregation-enhanced excimer emission effect. As an example, a copolymer, HBPE@Py@PGMA, that possesses an HBPE backbone simultaneously bearing pyrene terminal groups and poly(glycidyl methacrylate) (PGMA) side chains has been synthesized by combining Pd-diimine-catalyzed chain walking ethylene copolymerization and atomic transfer radical polymerization techniques, and epoxy resin-based composites have been obtained by physically mixing with the copolymer. It is found that while the PGMA side chains make the copolymer well dispersible in the epoxy resin matrix, the HBPE backbone can effectively promote the formation of intra/intermolecular pyrene excimers, thus rendering epoxy resin that can emit homogeneous and strong fluorescence even at extremely low pyrene concentrations (0.05–0.20 wt %). Representatively, other FPs also have been successfully prepared from the ethylene-vinyl acetate copolymer, poly(methyl methacrylate), and polystyrene by following this strategy.