Mechanical properties and inhomogeneous nanostructures of dicyandiamide‐cured epoxy resins

摘要: Dicyandiamide (DICY)-cured epoxy resins are important materials for structural adhesives and matrix fiber reinforced prepregs. The objective of this study was to examine the mechanical physical properties as well gel structures cured discuss relationships among them. Diglycidyl ether bisphenol-A (DGEBA) oligomers were chosen common chemical structure resins. Four kinds resin mixtures formulated using seven types DGEBA having different molecular weight distributions. Three formulations bimodal-type distributions designed have almost identical rubbery plateau values storage modulus in dynamic analyses after curing, means that they had equivalent average crosslink density basic structure. However, toughness, ductility, environmental (heat solvent) resistance these three different. Atomic force microscopy revealed existence inhomogeneous nanoscale morphological differences terms their size, connectivity, relative magnitude heterogeneity would cause difference several DICY-cured