Synthetic and Characterization Aspects of Dimethylaminoethyl Methacrylate Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization MEDHI SAHNOUN, 1 MARIE-THE ´ RE ` SE CHARREYRE, 1 LAURENT VERON, 1 THIERRY DELAIR, 1 FRANCK D’AGOSTO 2 1 Unite ´ Mixte CNRS-bioMe ´rieux, E ´ cole Normale Supe ´rieure de Lyon, 46 alle ´e d’Italie, 69364 Lyon Cedex 07, France 2 Laboratoire de Chimie et Proce ´de ´s de Polyme ´risation UMR 140 CNRS/ESCPE, Ba ˆt 308 F, 43 Boulevard du 11 Novembre 1918, BP 2077, 69616 Villeurbanne CEDEX, France Received 3 January 2005; accepted 7 March 2005 DOI: 10.1002/pola.20813 Published online in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: 2-cyanoprop-2-yl dithiobenzoate (CPDB) mediated RAFT polymerization of dimethylaminoethyl methacrylate (DMAEMA) was carried out in dioxane at 90 8C. The influence of several parameters, such as the monomer to CPDB molar ratio (100 to 500), the monomer concentration (2 mol  L 1 to 5.9 mol  L 1 ), and CPDB to initia- tor molar ratio (1 to 10), was evaluated with regards to conversion and polymerization duration, as well as control of molar mass and molar mass distributions. Number average molar masses from 10,000 to 70,000 g  mol 1 can be targeted. The determi- nation of the molar masses has been carried out by size exclusion chromatography (SEC) with a refractometer detector with poly(methyl methacrylate) (PMMA) stand- ards. The experimental values were lower than the expected ones. Then, SEC in aqueous medium with an online laser light scattering detector was used both to get absolute molar masses and to recalibrate the SEC column in THF. Characterization of well-controlled PDMAEMA samples has been performed by proton NMR spectro- scopy and matrix assisted laser desorption ionization time of flight mass spectro- metry. Finally, a chain extension experiment was evaluated with regard to living features. V V C 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3551–3565, 2005 Keywords: light scattering; MALDI; molecular weight distribution/molar mass distribution; reversible addition fragmentation chain transfer (RAFT); synthesis INTRODUCTION Among the water-soluble polymers, poly(dime- thylaminoethyl methacrylate) (PDMAEMA) is widely studied since it finds applications in various fields such as wastewater treatment, paints and coatings, filtration techniques, biol- ogy, and therapy. 1–4 DMAEMA (Scheme 1) has been homopolymerized 2,3,5–9 and copolymerized with methyl methacrylate, 2 aminoethyl metha- crylate, 7 and N-vinyl pyrrolidone, 10 to provide materials useful as ‘‘liants’’ for paints, 2 floccu- lants, 9 ion-exchange resins, 8 membranes, 3 and gene delivery systems. 5,7 These polymers are generally synthesized by the conventional free radical polymerization technique, which affords number average molar masses (M n ) in a wide range (from 2,500 to 360,000 g  mol 1 ) with, however, high polydispersity indices (PDI). To get narrow molar mass distributions (i.e., a more homogeneous material) and interesting top- ologies such as block copolymers, living/controlled polymerization techniques are required. Homopo- lymerization of DMAEMA was first unsuccess- fully carried out by living anionic polymeriza- Correspondence to: L. Veron (E-mail: laurent.veron@ ens-lyon.fr) and F. D’Agosto (E-mail: Franck.dagosto@lcpp.cpe.fr) Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 43, 3551–3565 (2005) V V C 2005 Wiley Periodicals, Inc. 3551