Poly(methyl methacrylate) (PMMA) was synthesized by activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) of MMA in ionic liquid-based microemulsion with polyoxyethylene sorbitan monooleate (Tween 80) as surfactant. The polymerization was carried out at 25 degrees C with CCl4 as initiator, FeCl3 center dot 6H2O/N,N,N,N-tetramethyl-1,2-ethanediamine (TMEDA) as catalyst complex in the presence of reducing agent ascorbic acid (VC). The polymerization kinetics showed the feature of controlled/living process as evidenced by a linear first-order plot. The well-controlled polymers were obtained with narrow polydispersity indices and the ionic liquid-based microemulsions were transparent with a particle size less than 30 nm. The obtained polymer was characterized by 1H NMR and gel permeation chromatography. The chain extension was successfully achieved by the obtained PMMA macroinitiator/FeCl3 center dot 6H2O/TMEDA/VC initiator system based on ARGET ATRP method. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013