Polymer Degradation by Synergistic Dual Stimuli: Base Interaction and Photocatalysis to Unlock a Boron Pendant Trigger for Main-Chain Scission
Hiroshi Makino, Tsuyoshi Nishikawa, Makoto Ouchi
Abstract
We used the carbon–boron (C–B) bond of a vinyl boronate unit as a trigger site to achieve the main-chain degradation of the copolymer through radical generation from the C–B trigger by the addition of a base (e.g., sodium methoxide) for interaction with Lewis acidic boron and subsequent photocatalysis with an organic photocatalyst. The C–B bond in the side chain and the carbon–carbon (C–C) bond in the main chain of the copolymers are thermally stable, but the copolymer underwent main-chain degradation via a β-scission triggered by unlocking the C–B bond through the synergistic dual stimuli for radical generation. The degradation was temporally controllable by turning the light on and off, and the significance of the C–B bond for the triggering degradation was demonstrated by control experiments and gel degradation.