A Novel Dynamic Polymer Synthesis via Chlorinated Solvent Quenched Depolymerization

Dynamic polymers with both physical interactions and dynamic covalent bonds exhibit superior performance, but achieving such dry polymers in an efficient manner remains a challenge. Herein, we report a novel organic solvent quenched polymer synthesis using the natural molecule thioctic acid (TA), which has both a dynamic disulfide bond and carboxylic acid. The effects of the solvent type and concentration along with reaction times on the proposed reaction were thoroughly explored for polymer synthesis. Solid-state proton nuclear magnetic resonance (¹H NMR) and first-principles simulations were carried out to investigate the reaction mechanism. They show that the chlorinated solvent can efficiently stabilize and mediate the depolymerization of poly(TA), which is more kinetically favorable upon lowering the temperature. Attributed to the numerous dynamic covalent disulfide bonds and noncovalent hydrogen bonds, the obtained poly(TA) shows high extensibility, self-healing, and reprocessable properties. It can also be employed as an efficient adhesive even on a Teflon surface and 3D printed using the fused deposition modeling technique. This new polymer synthesis approach of using organic solvents as catalysts along with the unique reaction mechanism provides a new pathway for efficient polymer synthesis, especially for multifunctional dynamic polymers.