Abstract: Atom transfer radical polymerization (ATRP) is one of the most powerful methodologies for polymerization. Well‐controlled ATRP of N‐isopropylacrylamide (NIPAAm) could be obtained in organic‐water mixture solvent with conventional metal catalyst/ligand catalyst system. However, the mixture solvent is not suitable for copolymerization of NIPAAm with hydrophobic monomers. Moreover, further purification of metal was required for biomedical polymerization. Here, poly(N‐isopropylacrylamide) (PNIPAAm) is synthesized by visible light–induced metal‐free ATRP using a photoredox catalyst. PNIPAAm is obtained with high conversion and controlled molecular weight with low dispersity. Moreover, poly(N‐isopropylacrylamide)‐block‐poly(tert‐butyl methacrylate) (PNIPAAm‐b‐PMAA) block copolymer can be synthesized by such metal‐free ATRP. PNIPAAm‐b‐PMAA can be obtained by following hydrolysis.
Reference: Xu, Y.; Li, G.; Hu, Y.; Wang, Y., Synthesis of Poly(N-isopropylacrylamide)-Block-Poly(tert-Butyl Methacrylate) Block Copolymer by Visible Light–Induced Metal-Free Atom Transfer Polymerization. Macromol. Chem. Phys. 2018, 219, 1800192.