Effect of substituted benzene group on thermal and mechanicalproperties of epoxy resins initiated by cationic latent catalysts

摘要

Epoxy resins (DGEBA) were cured by cationic latent thermal catalysts I.e., Nbenzylpyraziniumrnhexafluoroantimonate (BPH) and N-benzylquinoxaliniumrnhexafluoroantimonate (BQH) to investigate the effect of substituted benzene group onrnthermal and mechanical properties of epoxy system. Differential scanning calorimetryrn(DSC) was undertaken for activation energy of the epoxy system. It was alsorncharacterized in terms of Izod impact strengths for the mechanical tests. As a result, therncure reaction of both epoxy systems resulted in an autocatalytic kinetic mechanismrnaccelerated by hydroxyl groups. And, the conversion and cure activation energy ofrnDGEBA/BQH system were higher than those of DGEBA/BPH system. The impactrnstrength of DGEBA/BQH system was also superior to that of DGEBA/BPH system, asrnwell as the morphology. This was probably due to the consequence of the effect ofrnsubstituted benzene group of BQH catalyst, resulting in increasing the cross-link densityrnand structural stability in the epoxy system studied.