ATOMISTIC MODELING OF THE ADSORPTION OF EPOXY AND AMINE MOLECULES ON THE SURFACE OF CARBON-FIBERS

Atomistic molecular modelling was used to investigate theoretical diff erences in adsorption behaviour of the two major components in an epox y resin system. The model used quantum mechanical calculations to defi ne charges and bond angles within adsorbate molecules, and a charge eq uilibrium algorithm to define carbon fibre surface charges. The carbon fibre surface model was constructed with reference to data provided b y X-ray photoelectron spectroscopy. Modelling was undertaken using the 'Cerius(2)' software of Molecular Simulations Ltd. Probe molecules we re minimized onto the surface of the carbon fibre under the influence of the Dreiding 2.2.1 force held. Trends obtained from the modelled da ta were corroborated by independently derived inverse phase gas chroma tography (i.g.c.) data. Minimization of components of the epoxy resin 922 onto the carbon fibre surface showed that the epoxy molecule was m ore strongly attracted to the carbon fibre surface than the amine hard ener. Micromechanical testing provided evidence of an epoxy-rich inter phase.