Bulk Depolymerization of Polystyrene with Comonomer Radical Triggers
James B. Young, Jared I. Bowman, Megan E. Lott, Lily Diodati, Kaden C. Stevens, Rhys W. Hughes, Lauren E. Mann, Alex H. Balzer, LaShanda T. J. Korley, Brent S. Sumerlin
Abstract
This study introduces a novel approach to depolymerize polystyrene in the absence of solvent at significantly reduced temperatures through the incorporation of a thermally labile comonomer. Specifically, we employ N -(methacryloxy)phthalimide (PhthMA) as a comonomer with an activated ester capable of thermally triggered decarboxylation. Thermal treatment enables the generation of backbone radicals that promote β -scission and subsequent unzipping. These polystyrene analogs depolymerize with up to 91% reversion to monomer in under 2 h at temperatures significantly lower than those required for conventional polystyrene. As compared to depolymerization triggered by decarboxylation at the ω -chain end, this pendent-group approach was considerably more efficient. The recovered styrene monomer from the bulk depolymerization of poly(styrene- co -PhthMA) copolymers can undergo direct repolymerization, yielding new styrenic materials. This comonomer strategy extends across various styrenic copolymers, highlighting its potential as a broadly applicable method for initiating depolymerization among vinyl polymer classes.