Upcycling Commodity Styrofoam into Redox Polymer-based Electrodes

Abstract

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.