A novel method for surface modification of UV-cured epoxy network was described. Photoinitiated cationic copolymerization of a bisepoxide, namely 3,4-epoxy cyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (EEC) with epibromohydrine (EBH) by using a cationic photoinitiator, [4-(2-methylpropyl)phenyl]4-methylphenyl-iodonium hexafluorophosphate, in propylene carbonate solution was studied. The real-time Fourier transform infrared spectroscopic, gel content determination and thermal characterization studies revealed that both EEC and EBH monomers take part in the polymerization and epoxy network possessing bromomethyl functional groups was obtained. The bromine functions of the cured product formed on the glass surface were converted to azide functionalities with sodium azide. Independently prepared alkyne functional poly(ethylene glycol) (PEG) was subsequently anchored to azide-modified epoxy surface by a "click" reaction. Surface modification of the network through incorporation of hydrophilic PEG chain was evidenced by contact angle measurements. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2862-2868, 2010