EFFECTS OF MORPHOLOGY ON TOUGHENING OF TETRAFUNCTIONAL EPOXY-RESINS WITH POLY(ETHER IMIDE)

Tetraglycidyl-4,4'-diaminodiphenyl methane based resin with 30 phr diaminodiphenyl sulfone as curing agent was toughened with poly(ether imide) (PEI). The effects of morphology on the fracture toughness of modified epoxy resins were investigated. Morphology was controlled by changing the curing conditions. The co-continuous structure and morphology of the PEI spherical domain dispersed in the epoxy matrix were obtained. Phase-inversed morphology with PEI matrix was also obtained with 30 phr PEI content. The cured resin with phase-inversed morphology showed the highest fracture toughness. The modified epoxy resins with enhanced fracture toughness exhibited other improved mechanical properties such as flexural strength, flexural modulus and strain at break.