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

Tetraglycidyl-4,4'-diaminodiphenyl methane based resin with 30 phr dia minodiphenyl sulfone as curing agent was toughened with poly(ether imi de) (PEI). The effects of morphology on the fracture toughness of modi fied epoxy resins were investigated. Morphology was controlled by chan ging the curing conditions. The co-continuous structure and morphology of the PEI spherical domain dispersed in the epoxy matrix were obtain ed. Phase-inversed morphology with PEI matrix was also obtained with 3 0 phr PEI content. The cured resin with phase-inversed morphology show ed the highest fracture toughness. The modified epoxy resins with enha nced fracture toughness exhibited other improved mechanical properties such as flexural strength, flexural modulus and strain at break.