Thermal stabilities and dynamic mechanical properties of sulfone-containing epoxy resin cured with anhydride

A sulfone-containing epoxy resin, the diglycidylether of bisphenol-S (DGEBS), was obtained and its structure was confirmed by means of FT-IR, ¹H NMR, ¹³C NMR spectra, and elemental analysis. Curing behaviours, thermal stabilities, and dynamic mechanical properties of the DGEBS resin cured with phthalic anhydride (PA) and tetrahydrophthalic anhydride (THPA) as curing agents were studied using dynamic differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). The cure reaction of the DGEBS/anhydride systems was initiated at a relatively low temperature in the presence of tertiary amine. The DGEBS/THPA/DMBA system showed higher glass transition temperature, initial decomposition temperature, and activation energy for decomposition than those of the DGEBS/PA/DMBA system, which was attributed to the higher cross-linking density of the DGEBS/THPA/DMBA system.