Selective polymerization of glycidyl methacrylate (GMA), which has two polymerizable functional groups such as epoxide and methacrylate, was achieved by the monomer-activated anionic approach using tetraoctylammonium bromide/triisobutylaluminum initiating system in toluene at 20 degrees C. Quantitative and controlled synthesis of poly(glycidyl methacrylate ether), up to about 20 000 g/mol, with pendant methacrylate functions, was obtained by ring-opening of the epoxide. The copolymerization of glycidyl methacrylate with glycidyl methyl ether (GME) in similar conditions, the resulting copolyether structures, and their properties were investigated as a function of feed composition. Reactive poly(glycidyl methyl ether-co-glycidyl methacrylate ether)s P(GME-co-GMA) with lower critical solubility temperature depending on the ratio [GME]/[GMA] were prepared and analyzed by NMR spectroscopy and differential scanning calorimetry. Postpolymerization cross-linking reactions of PGMA and random P(GME-co-GMA) copolymers were investigated by infrared spectroscopy and water contact angle measurements under heating or UV irradiation.