Photocontrolled iodine-mediated reversible-deactivation radical polymerization with a semifluorinated alternating copolymer as the macroinitiator

• Published in: Polymer chemistry 2020-12, Vol.11 (47), p.7497-755
• Main Authors: Cheng, Jiannan, Tu, Kai, He, Enjie, Wang, Jinying, Zhang, Lifen, Cheng, Zhenping, Zhu, Xiulin
• Format: Article
• Language: English
• Subjects: Acetone; Acrylates; Block copolymers; Deactivation; Fluoropolymers; Iodine; Light emitting diodes; Light irradiation; Perfluoroalkyl & polyfluoroalkyl substances; Polymer chemistry; Polymerization; Room temperature
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/d0py01357a

A new photocontrolled iodine-mediated reversible-deactivation radical polymerization (RDRP) strategy to facilely prepare main-chain-type semifluorinated alternating block copolymers was successfully established under irradiation with blue LED light at room temperature, by using a semifluorinated alternating copolymer ((AB) n , where A represents α,ω-diiodoperfluoroalkane and B represents α,ω-unconjugated diene) as a macroinitiator and chain-transfer agent, and methacrylates, acrylates and styrene as the monomers. The end group of (AB) n terminated with perfluoroalkyl iodide -(CF 2 ) n -I can be activated by Ru(bpy) 3 Cl 2 /AsAc-Na reducing quenching catalytic cycle which generates initial carbon centered radicals (-(CF 2 ) n &z.rad;) to initiate the polymerization under blue LED light irradiation. The polymerization can reach a reversible equilibrium through effective oxygen-iodine halogen bonding in acetone and undergo a photocontrolled iodine-mediated RDRP process. In addition, the "living" features of this photocontrolled iodine-mediated RDRP system were confirmed by polymerization kinetics and controlled "on-off" light switching cycle regulation. What's more, different types of fluoropolymers can be introduced on the copolymer chains due to the powerful designability of (AB) n . Therefore, this strategy can provide a facile and highly efficient approach to the precision synthesis of main-chain-type semifluorinated alternating di/triblock polymers under visible light irradiation. A novel strategy for preparing block copolymers with semifluorinated alternating copolymers as macroinitiators was established by photocontrolled iodine-mediated RDRP under irradiation with blue LED light at room temperature.