ARGET ATRP of methyl methacrylate in the presence of nitrogen‐based ligands as reducing agents

Abstract

AbstractBACKGROUND: Activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP) employs reducing agents (e.g. ascorbic acid, tin(II) 2‐ethylhexanoate) to continuously reduce a deactivator Cu(II) to an activator Cu(I) species. In this work, copper‐mediated ARGET ATRP of methyl methacrylate (MMA) was studied in the presence of excess aliphatic nitrogen‐based ligands that served not only as ligands but also as reducing agents.RESULTS: Reduction of Cu(II) to Cu(I) by an excess amount of nitrogen‐based ligand was followed by UV‐visible spectroscopy. Well‐controlled poly(methyl methacrylate) (PMMA) with low polydispersity index (PDI) was prepared in the presence of Cu(II)Br2/excess ligand via ARGET ATRP. Chain extension of PMMA with MMA was successful, resulting in low‐PDI PMMA and demonstrating well‐maintained end‐group functionality.CONCLUSION: Well‐controlled PMMA with low PDI was prepared via ARGET ATRP in the presence of Cu(II) and nitrogen‐based ligands without any additional reducing agent. Aliphatic nitrogen‐based ligands for ATRP can serve as reducing agents as well as ligands. Copyright © 2009 Society of Chemical Industry