Successive visible light-controlled synthesis of block copolymers by combination of BIT-RDRP and ROP strategy.

[Display omitted] • Block copolymers synthesised through sequential NIR LED light-controlled BIT-RDRP and purple LED light induced ROP strategy. • The dispersity value of the block copolymers can be as low as to 1.06. • The "one pot" strategy greatly simplified the operation process and improved the synthesis efficiency. Photoinduced reversible-deactivation radical polymerization (RDRP) has attracted great interest in virtue to their unique inherent advantages, such as low activation energy, environmentally benign reaction conditions and precision synthesis of designable functional polymeric materials. In this work, a facile and efficient strategy for preparing block copolymers was developed by the combination of near-infrared (NIR) light-controlled in-situ bromine-iodine transformation reversible-deactivation radical polymerization (BIT-RDRP) and purple LED light induced ring-opening polymerization (ROP). Herein, the macroinitiator was first synthesized via NIR light-controlled BIT-RDRP by using a bifunctional 2-hydroxyethyl 2-bromo-2-phenylacetate (EBP-OH) as the initiator at room temperature. Subsequently the block copolymers with narrow dispersity (low up to 1.06) were prepared by combination of purple LED light induced ROP through "two step" or "one pot" process. Importantly, the "one pot" strategy can greatly simplify the operation process and improve the synthesis efficiency, which will facilitate the batch preparation of block copolymers. [ABSTRACT FROM AUTHOR]