Paper number 1036

INTERFACE ADHESION IN COMPOSITES. CORRELATION BETWEEN IGC MEASUREMENTS AND MECHANICAL TESTING RESULTS.

S. Santa1, M.C. Gutiérrez1, J. Rubio2

1Departamento de Materiales Compuestos, Instituto Nacional de Técnica Aeroespacial
Ctra. Ajalvir Km 4, 28050 Torrejón de Ardoz. Madrid. Spain
2Instituto de Cerámica y Vidrio. (CSIC). Ctra. Valencia Km.24.3, 28500. Arganda del Rey. Madrid. Spain

Summary The main role of the interface in a CFRP is to transfer the load from the stiff carbon fibres to the soft matrix material. The good interaction between both components of the composite governs the efficiency of this transference process. This adhesion is the result of many phenomena: mechanical gripping and physicochemical adsorption, principally. This adhesion relies on the free groups in the surface of the fibres, and the chemical composition of the resins. The strength of the interface is of vital importance in the behaviour of the composite. The deep knowledge of these surface groups and the quantification of the interface interaction has been the subject of much research effort.
Inverse Gas Chromatography (IGC) has proved to be one of the most valuable and available tools for evaluation of the characteristics of solid surfaces that cannot be easily studied by other methods, like powders and fibres. There are several methods described in the literature for the evaluation of the non-polar character, and the acid and basic character of the free surface energy by IGC, we have recently proposed a new method for the evaluation of the polar part or specific component of the free energy of a solid surface and its application to CFRP. The ILSS test or determination of the apparent interlaminar shear strength, in principle, gives information about the matrix-fibre interface.
Keywords interface, inverse gas chromatography, apparent interlaminar shear strength, carbon fibres, epoxy resin, cyanate ester resin, surface characteristics, matrix characteristics.

Theme : Interface and Interphase ; Physical Properties

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