Selective Electrocatalytic Degradation of Ether-Containing Polymers

Leveraging electrochemistry to degrade robust polymeric materials has the potential to impact society's growing issue of plastic waste. Herein, we develop an electrocatalytic oxidative degradation of polyethers and poly(vinyl ethers) via electrochemically mediated hydrogen atom transfer (HAT) followed by oxidative polymer degradation promoted by molecular oxygen. We investigated the selectivity and efficiency of this method, finding our conditions to be highly selective for polymers with hydridic, electron-rich C-H bonds. We leveraged this reactivity to degrade polyethers and poly(vinyl ethers) in the presence of polymethacrylates and polyacrylates with complete selectivity. Furthermore, this method made polyacrylates degradable by incorporation of ether units into the polymer backbone. We quantified degradation products, identifying up to 36 mol % of defined oxidation products, including acetic acid, formic acid, and acetaldehyde, and we extended this method to degrade a polyether-based polyurethane in a green solvent. This work demonstrates a facile, electrochemically-driven route to degrade polymers containing ether functionalities. Electrochemically mediated hydrogen atom transfer (HAT) followed by oxidative polymer degradation promoted by molecular oxygen provides an electrocatalytic degradation of polymers with activated C-H bonds, such as polyethers, poly(vinyl ethers), and polyether-based polyurethanes. A study of the mechanism, selectivity, and efficiency of this method led to the identification of oxidized small-molecule degradation products.+image

Automated summary

This study demonstrates a method to degrade polymers using electrochemistry, and investigates the selectivity and efficiency of the process. Electrocatalytic degradation of polymers with activated C-H bonds is achieved through oxidative polymer degradation promoted by molecular oxygen and electrochemically mediated hydrogen atom transfer (HAT).