450. Bulk depolymerization of poly(methyl methacrylate) via chain-end initiation for catalyst-free reversion to monomer

James B. Young, Rhys W. Hughes, Ariana M. Tamura, Laura S. Bailey, Kevin A. Stewart and Brent S. Sumerlin, Chem (2023), DOI: 10.1016/j.chempr.2023.07.004

We present the bulk depolymerization of poly(methyl methacrylate) (PMMA) at significantly lower temperatures than previously reported methods through the incorporation of thermolytically labile end-groups via reversible-deactivation radical polymerization (RDRP). The combination of α-end N-hydroxyphthalimide esters and ω-end trithiocarbonates allows for near-quantitative depolymerization of PMMA in the bulk, with >90% methyl methacrylate (MMA) recovery for subsequent repolymerization. This depolymerization methodology enables catalyst- and solvent-free reversion to monomer on a multigram scale at temperatures up to 250°C lower than current industrial methods. These reactions are performed in an efficient and high-yielding manner, establishing a viable route to depolymerize PMMA on large scales.