The reaction of styrene-maleic anhydride with a low molecular weight polytetramethylene ether glycol was studied in an intensive batch mixer and in a corotating twin screw extruder. The reaction mixtures were later compression molded in the form of films. The films analyzed by FTIR spectroscopy showed the presence of both carboxylic acid and ester groups. Physical and mechanical properties of the materials were evaluated at different reactive processing conditions. The glass transition temperature of the mixed products and the tensile modulus of the prepared films decreased with increasing PTMEG concentration due to the plasticization effect of the polyol.