Star-shaped alkylated poly(glycerol methacrylate) reverse micelles: Synthesis and evaluation of their solubilizing properties in dichloromethane

Amphiphilic star-shaped polymers were synthesized by atom transfer radical polymerization (ATRP). Four-, 5-, and 6-arm ATRP initiators were prepared and used to polymerize glycidylmethacrylate. The resulting polymers were hydrolyzed to yield poly(glycerolmethacrylate)s (PG_OHMAs), and then partially esterified with lauroyl or stearoyl chloride (40–60 mol % vs. hydroxyl groups). Alkylated PG_OHMAs were found to assemble into 20–60 nm aggregates in dichloromethane (DCM) above a critical concentration. Particle size essentially depended on the branching degree of the polymer. The micelles were extremely efficient in extracting Congo red from water into DCM, with the highest incorporations (97 mg/g) obtained for the 6-arm polymer modified with stearoyl chloride (60 mol %). The entrapment efficiency for the latter was further improved in alkaline solution. The high level of incorporation achieved for these amphiphilic multiarm polymers suggests that such reverse micelles could be potentially useful as drug delivery systems and nanoreactors in catalytic organic reactions or for water purification. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2425–2435, 2007