Hyperbranched polymethacrylates with hydroxyl end groups were prepared by means of self-condensing vinyl oxyanionic polymerization of commercially available monomer 2-hydroxypropyl methacrylate. The hyperbranched polymers with high molecular weight were obtained with the complex of potassium hydride and 18-crown-6 as the initiator. The molecular structure of the hyperbranched polymers was confirmed with ¹H and ¹³C NMR spectra. The amount of initiator used in the polymerization could affect the structure of polymer based on a proton-transfer process. The glass transition temperature of the prepared polymers ranged from 58.1 to 81.4 ℃, and decreased with decreasing the initiator to monomer ratio. When the ratio of initiator to monomer equaled 1, the degree of branching of the resulting polymer was calculated to be 0.49.

Key words: hyperbranched polymer, self-condensing vinyl polymerization, 2-hydroxypropyl methacrylate, oxyanionic polymerization