A novel quaternary amine methacrylate monomer (QAMA) was synthesized by amination of dimethacrylate with piperazine followed by its quaternization using an alkyl iodide. Copolymerization of QAMA with 2-hydroxyethyl methacrylate was carried out by free radical bulk polymerization technique at room temperature using ammonium persulfate and N,N,N',N'-tetramethyl ethylenediamine as a redox initiator. The monomer as well as copolymers was, characterized by FTIR and H-1 NMR spectral studies. Thermal and physical characteristics of copolymers of varying compositions of QAMA were evaluated by thermogravimetric analysis, differential calorimetry, contact angle and scanning electron microscopy. The antibacterial activity of the synthesized quaternary amine dimethacrylate copolymers against Escherichia coli and Staphylococcus aurcus was studied by zone of inhibition and colony count method. QAMA copolymers showed broad-spectrum contact killing antibacterial properties without releasing any active agent as checked by iodide-selective ion meter. (c) 2006 Wiley Periodicals, Inc.