Defect-free acrylic polymers with a near-Poisson distribution prepared via catalyst-free visible-light-driven radical polymerization

Abstract

Reversible-deactivation radical polymerization (RDRP) based on direct photolysis has a favorable reaction structure for superior controllability compared to that of conventional RDRP. However, this aspect has not been fully demonstrated because the photolysis process is vaguely understood. In this study, we propose a mechanism for photolysis and apply the proposed mechanism to obtain polyacrylates with an extremely narrow dispersity approaching the Poisson distribution (an ideal molecular weight distribution attained in living polymerization) and a negligible fraction of dead chains (< 2%), even for very high conversion (> 90%) and short reaction time (5 h). Based on the results, extremely well-defined and defect-free a,w-hydroxyl end-functionalized polyacrylates were prepared to utilize the resulting polyols as soft segments of thermoplastic polyurethane (TPU) elastomer. Using the prepared polyols, TPU elastomers that do not follow the conventional trade-off relationship of strength-elongation and robustness-self healing ability were successfully prepared, highlighting their potential as next-generation functional polymeric materials.