Morphologies of cured epoxy /brominated-phenoxy blends were observed by scanning transmission electron microscopy (STEM) and energy dispersive X-ray fluorescence spectroscopy (EDX). When brominated-phenoxy content was 30 wt %, cocontinuous phase structures between cured epoxy and brominated-phenoxy were found. Since every loss tangent (tan 8) curve as a function of temperature on dynamic mechanical analysis (DMA) showed 2 peaks at 128 degrees C and 155 degrees C respectively, cured epoxy phases and brominated-phenoxy phases were incompatible together and T(g)s of cured epoxy phases were not decreased. Tensile strength and tensile elongation of the cured blends were increased together. T-peel adhesion strength and the lap-shear adhesion strength were also increased together. These phenomena could be due to the cocontinuous structures consisted by the rigid cured epoxy phases of thermosets and ductile the brominated-phenoxy phases of thermoplastics. (c) 2007 Wiley Periodicals, Inc.