Facile Synthesis of Unimodal Polymethacrylates with Narrow Dispersity via NIR LED Light‐Controlled Bromine–Iodine Transformation Reversible‐Deactivation Radical Polymerization

Abstract A facile and clean strategy for synthesizing unimodal polymethacrylates with narrow dispersity ( Đ < 1.10) is successfully developed by a near‐infrared (NIR) light‐emitting diode (LED) light ( λ max = 740 nm)‐controlled in situ bromine–iodine transformation reversible‐deactivation radical polymerization system without the use of NIR dyes and expensive catalysts. In this system, alkyl iodide ethyl α ‐iodophenylacetate (EIPA) initiator is generated in situ by the nucleophilic substitution reaction between an alkyl bromide compound ethyl α ‐bromophenylacetate and sodium iodide (NaI). At the same time, excessive NaI is also acted as a highly active catalyst by forming halogen bonds with terminal iodine of the polymer chains in this system to make it capable of precisely synthesizing polymethacrylates with narrow dispersities ( Đ = 1.03–1.10). In addition, the strong penetration ability of NIR LED light is illustrated by the successful polymerization even through 11 pieces of A4 paper.