Retrofitting PMMA with a Thermal Trigger for Efficient Depolymerization

This work reports an efficient closed-loop bulk depolymerization method applicable to commercially available PMMA. Acid hydrolysis (<10%) and subsequent esterification with <i>N</i>-hydroxyphthalimide are used to incorporate a thermally sensitive trigger that allows efficient depolymerization of PMMA at a temperature lower than conventionally employed. We showed that this strategy is applicable to model PMMA homopolymers with molecular weights ranging from 28 to 1140 kg/mol. The same method was used for efficient bulk depolymerization (∼70%) of commercially available PMMA (<i>M</i>_n = 439 kg/mol), supporting the efficacy of this work for practical applications. Furthermore, we demonstrate that this method can be leveraged to generate depolymerizable polymer networks. The depolymerization approach reported here holds potential to mitigate polymethacrylate waste and maintain a sustainable polymer economy.