Electrochemical C-H Functionalization and Defunctionalization of Polystyrene.

Covalent modification of simple commodity polymers by C-H functionalization is an efficient way to access new structure-property characteristics and a promising strategy for repurposing plastic waste. We developed an electrochemical method for preparing sulfonium polyelectrolytes by C-H functionalization of polystyrene (PS) from simple thianthrenes. This methodology affords access to structurally diverse polysulfonium products with a controllable degree of functionalization and tunable properties. Modular access to new thianthrenium-functionalized PS materials in this fashion enabled detailed structure-property studies, which revealed that the thianthrenium polymers exhibit high thermal stability, multiphase behavior, and photochemical reactivity that introduces photoacid generator functionality and the ability to undergo defunctionalization.