Maleimide functionalized copoly(urethaneurea)s were prepared by the reaction of a binary mixture of dibenzyldiisocyanate and 5-maleimidosophthalic diisocyanate with a macrodiol (PEGA-2000), using diethylene glycol and trimethylol-propane as chain extender and crosslinkers in toluene-dichloromethane solutions at the ratio NCO/OH = 1.2. structures of polymers were confirmed by IR spectroscopy and properties were studied by thermal and mechanical analysis (dynamic mechanical analysis (DMA), differential scanning calorimetry, thermogravimetric analysis, stress-strain) and other physical methods. Maleimide modification increased the storage modulus and Young's modulus Of copoly(urethane-urea)s, slightly increased their glass transition temperature from -10.6 degrees C to -6.3 degrees C. Copoly(urethane-urea) networks obtained by thermal polymerization of maleimide functions Showed Significantly increased of the mechanical properties. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3245-3254, 2009