Development of a Robust PET-RAFT Polymerization Using Graphitic Carbon Nitride (g‑C₃N₄)

The metal-free semiconductor, graphitic carbon nitride (g-C₃N₄), was introduced into RAFT polymerization for the first time. The production of linear polyacrylate and polyacrylamide has been achieved via PET-RAFT polymerization using g-C₃N₄ as a photoactive organocatalyst without prior deoxygenation. The resulting polymers display controlled molecular weights, narrow polymer dispersities, and high end-group fidelity as exemplified by ¹H NMR analysis, MALDI-TOF-MS measurement, and chain extension experiment. Temporal control is illustrated by intermittent light and dark cycles, with polymer growth arrested in the absence of irradiation. The effects of changing RAFT agents (i.e., trithiocarbonates), solvents, catalyst concentrations, and degrees of polymerization in this system have been investigated. The successful polymerization of nonpurified monomer (i.e., still containing radical inhibitors) demonstrates the robust nature of the presented PET-RAFT system.