AGET ATRP of Poly[poly(ethylene glycol) methyl ether methacrylate] Catalyzed by Hydrophobic Iron(III)-Porphyrins

Commercially available hydrophobic porphyrins are investigated as an environmentally friendly catalytic system for iron-mediated atom transfer radical polymerization (ATRP) of poly(ethylene glycol) monomethyl ether methacrylate (PEGMA). Polymerizations in organic solvent are optimized using activators generated by electron transfer (AGET ATRP), based on iron(III)-porphyrin complexes, and tin(II) 2-ethyl hexanoate or ascorbic acid as a reducing agent. Copper-free PPEGMA macromolecules are obtained with high conversion, controlled molecular weight, and polydispersity index compared with standard copper-based ATRP. The facile preparation and availability of the catalyst, together with its expected low toxicity, represent clear advantages for the synthesis of PPEGMA-based materials for biomedical use.