Polymethylmethacrylate (PMMA) and bisphenol-A-polycarbonate (PC) polymer blends are prepared by solution casting technique using tetrahydrofuran as a solvent. The structural properties of the polymer blends before and after they had been irradiated to electron beam accelerator was investigated by color strength, scanning electron microscopy (SEM), and FTIR spectroscopy. The thermal properties such as TGA and DSC were investigated. The TGA thermograms showed that the thermal stability of the unirradiated polymer blends PMMA/PC increases with increasing the ratios of PC component in the blend. Also, it was found that the presence of PC polymer in the blend affords protection against radiation degradation and improves their thermal stability. The DSC scans show a single Tg intermediate between PMMA and PC indicate the existence of specific interactions between PMMA and PC polymers in the blend. An intimate blends are reflected by substantial shifts in the frequencies of the PMMA and PC C?O vibration obtained by FTIR. SEM confirms the homogeneity of the blend. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125:31843190, 2012