Emission-tunable aggregation-induced emission thermoplastics via ketyl-mediated polymerization-induced emission

Abstract

Thermoplastics are an important class of polymer materials and dominantly used in industries because of their versatility, remoldability, cost performance, etc.; however, they are mainly used as matrices and lack functionalities, e.g., luminescence. Herein, a ketyl-mediated polymerization-induced emission (KMPIE) strategy is demonstrated to achieve emission-tunable aggregation-induced emission (AIE) thermoplastics, including a general thermoplastic (polystyrene as an example) and a degradable thermoplastic (polycaprolactone as an example). Through KMPIE of styrene and caprolactone in the presence of different enone initiators, polystyrene and polycaprolactone with different end groups were prepared with emission-tunable AIE properties from blue to green. Investigations revealed that a single-fluorophore end group can trigger different nontraditional intrinsic luminescence (NTIL) in AIE polystyrene and polycaprolactone with quantum yields of up to >20%. Investigations into further applications in explosive detection at ppm levels in solution and ng levels on test paper and in enhancement of luminescence in films were carried out. Chemical degradation of the prepared thermoplastics was investigated as well. This work therefore expands the functionality library of general and degradable thermoplastics with AIE-type NTIL properties and may inspire developments in luminescent materials, polymer chemistry, NTIL, AIE and PIE.