Energetic block copolymer of polyglycidylazide-b-poly (azidoethyl methacrylate) (GAP-b-PAEMA) was synthesized and characterized. Macroinitiator PECH-Br prepared via the reaction of 2-bromoisobutyryl bromide with hydroxyl-terminated polyepichlorohydrin (PECH-OH) was used to initiate the atom transfer radical polymerization (ATRP) of chloroethyl methacrylate (CEMA). After azidation of the resulting copolymer, energetic copolymer GAP-b-PAEMA was obtained. Increase in the molecular weight determined by gel permeation chromatograph (GPC) is in agreement with the formation of block copolymer. Fourier transform infrared spectroscopy (FTIR) shows that the chlorine groups in the block copolymer can be substituted by azide group easily. Thermogravimetric analysis (TGA) shows that degradation of GAP-b-PAEMA involves two steps: the instantaneous decomposition of the azide groups followed by progressive scission of the polymer backbone. From differential scanning calorimetry (DSC) analysis, the GAP-b-PAEMA copolymer exhibits two glass transition temperatures (T-g) at -18 and 36 degrees C, suggesting that the synthesized copolymer is a thermoplastic elastomer. This research provides a new method for the synthesis of energetic polymer. POLYM. ENG. SCI., 52:768-773 2011. (C) 2011 Society of Plastics Engineers