Rheological and mechanical properties of DGEBA-S epoxy copolymer initiated by N-benzylquinoxalinium hexafluoroantimonate

The rheological and mechanical properties of the DGEBA-S epoxy copolymer initiated by N-benzylquinoxalinium hexafluoroantimonate (BQH) as a cationic latent thermal catalyst were investigated. The rheological properties of the DGEBA-S/BQH system were investigated using a rheometer under isothermal conditions, and the mechanical properties of the casting specimens, involving flexure and impact tests, were also performed. The crosslinking activation energy and mechanical properties of the DGEBA-S/BQH system were higher than those of the DGEBA/BQH system. This could be attributed to the introduction of sulfone groups with a polar nature to the main chain of the epoxy resins which led to a decrease of molecular motion and an improvement in the toughness of the cured epoxy copolymers.