Effect of the interphase microstructure on the behavior of carbon fiber/epoxy resin model composite in a thermal environment

The effect of the interfacial microstructure on the stress transfer for a single-fiber carbon fiber/epoxy matrix composite with two different levels of fiber–matrix adhesion for a temperature range between 25 and 115 °C was studied. The heterogeneity of the matrix in the neighborhood of the fiber on the effective mechanical properties of the composite and the possible interactions fiber–matrix that could lead to the development of an interphase dissimilar to the bulk matrix were also analyzed. The preferential absorption of one component of the matrix on the carbon fiber surface is considered to play a key factor on the interfacial behavior for a varying temperature. The matrix-interphase amine-resin stoichiometry is considered to be the main parameter controlling the single-fiber composite behavior when exposed to high temperature.