Physico-Chemical Interactions between Carbon Fibers and Peek

Abstract

The adhesion between the polymer matrix and the reinforcing fiber plays a major role on the final performances of a composite. This adhesion can be estimated if the surface properties of the fiber and the matrix are known. In this study, the dispersive component of the surface energy and the electron acceptor-donor characters of PEEK powder and different untreated and surface treated carbon fibers are determined by means of inverse gas chromatography at infinite dilution. An estimation of the total work of adhesion at carbon fiber-matrix interface can therefore be proposed. The interfacial shear strength at this interface is also determined by fragmentation test on single fiber composite using an acoustic emission measuring device. A linear relationship between this interfacial shear strength and the estimated adhesion energy is established, showing that physico-chemical interactions between the fiber and the matrix greatly determine the mechanical behavior of the fiber-matrix interface.