INTERPHASE IN EPOXY COMPOSITES.

This paper introduces the concept of an interphase in epoxy composites as being an identifiable entity which in some circumstances can control properties. The review is divided into two major parts. The first describes the interphase from a phenomenological viewpoint as to its possible structure and composition. Examples are given which serve to illustrate the potential for inducing compositional and structural differences at the reinforcement surface-epoxy interface. The second portion uses the results of micromechanical modeling of ideal composites to illustrate the magnitude and type of forces which operate in the interphase region. Specific examples are included which quantify the relationship between interphase structure and composite mechanical and fracture properties.