The sulfonyl epoxy monomer (SEP) was synthesized and further to blend with the diglycidyl ether of bisphenol A (DGEBA). The glass transition temperature (T-g) of the SEP/DGEBA blended materials increased from 103.7 to 163.8 degrees C. The cross-linking density and polymer chain self-association intra-molecular action affected more than that the polymer-polymer intermolecular action (hydrogen bonding) in the SEP blended with the DGEBA materials. The excess stabilization energy in the overall stabilization was only 0.00145% (14.5 ppm), which indicated that the polymer-polymer intermolecular action was weak. The thermal degradation of the SEP segments could form various sulfate derivatives at lower temperature and analyzed by the TGA/GC/Mass. The sulfate derivatives could generate the thermal stable chars, which provided the "shielding effect" and antioxidation property. Additionally, these chars could also improve the protective effect and inhibit the thermal-oxidation decomposition under the air atmosphere. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 2165-2175, 2010