Bisphenol-A glycidyl ether epoxy resin was modified using reactive poly(ethylene glycol) (PEO). Dynamic mechanical analysis showed that introducing PEO chains into the structure of the epoxy resin increased the mobility of the molecular segments of the epoxy network. Impact strength was improved with the addition of PEO at both room (RT) and cryogenic (CT, 77 K) temperature. The curing kinetics of the modified epoxy resin with polyoxypropylene diamines was examined by differential scanning calorimetry (DSC). Curing kinetic parameters were determined from nonisothermal DSC curves. Kinetic analysis suggested that the two-parameter autocatalytic model suitably describes the kinetics of the curing reaction. Increasing the reactive PEO content decreased the heat flow of curing with little effect on activation energy (Ea), pre-exponential factor (A), or reaction order (m and n). (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012