Upcycling Commodity Styrofoam into Redox Polymer-based Electrodes

Commodity polystyrene from styrofoam food boxes was chemically transformed into redox-active organic polymers via a two-step functionalization sequence. In the first step, controlled chloromethylation of the pendent phenyl rings was used to functionalize 30-50 % of the polymer chain. The degree of functionalization could be tuned by simply varying the reaction time (1-3 h). Next, phenothiazine or nitroxide radical moieties were introduced via nucleophilic displacement of the benzylic chlorides to afford polymers with redox-active pendent sidechains. These phenothiazine and TEMPO-functionalized polymers were then characterized electrochemically to demonstrate their redox properties and evaluate their performance as battery electrodes. Overall, this process serves as proof-of-concept for the rapid conversion of consumer-grade styrofoam into redox-active polymers with the potential to serve as metal-free electrodes in organic batteries.