An Automated Flow Platform for the Rapid Synthesis and Degradation of Lipoic-Acid Based Copolymers

Abstract

Batch photopolymerization is often limited by insufficient light penetration, heat accumulation, and kinetic inhomogeneity, which hinder precise control over polymer structure and scalability. Here, we demonstrate a continuous-flow synthetic platform that integrates photoinduced polymerization and thermally driven degradation within a single system. Using n-butyl acrylate and bioderived α-lipoic acid monomers, statistical copolymers were rapidly synthesized under low light intensity (365 nm, 6 mW/cm2) within 360 s while maintaining quantitative and steady-state conversion over a 100-fold scale-up, achieving a productivity of 1.36 kg/L/h (44 g/day). In-line ultraviolet–visible (UV–vis) monitoring confirmed constant and predictable conversion from a stable radical flux across the residence-time distribution, evidencing homogeneous photon and mass transport even under weak irradiation. Remarkably, the resulting copolymers underwent thermal degradation to oligomers within 4 h, also under continuous-flow conditions, without any catalyst, enabling efficient degradation and reuse. This reversible photothermal flow process highlights the potential of a scalable chemical system that enables polymerization, depolymerization, and repolymerization for the design of dynamic and degradable materials.