Effect of Particle-Surface-Modification on the Failure Behavior of Epoxy/Boehmite CFRPs

Abstract

This chapter deals with the effect of particle content (up to 15 wt%) and particle surface modification on the mechanical properties (tensile properties and fracture toughness) of epoxy/boehmite composites. Furthermore, the failure behavior of epoxy/boehmite carbon fiber reinforced polymers (CFRPs) is investigated with compression after impact (CAI) tests at a constant fiber volume fraction of approximately 60 vol%. The CFRPs are fabricated by the Resin Transfer Moulding (RTM) method. To investigate the effect of particle-matrix-interaction, boehmite nanoparticles with different surface modifications (carboxylic acids and (3-aminopropyl)-triethoxysilane) are used. The epoxy/boehmite masterbatches used for the preparation of the specimens are characterized concerning particle sizes and surface loadings to ensure a comparability of the test results. The used masterbatches possess nearly the same size distributions and surface loadings. In addition viscosity measurements showed that the processability of the modified resins is strongly affected by modifying the surface of the boehmite particles. The mechanical tests show that the examined mechanical properties of the epoxy/boehmite composites as well as the failure behavior of the epoxy/boehmite CFRPs are mainly influenced by the filler content. The effect of particle surface modification is visible in particular for tensile modulus of the epoxy/boehmite composites. In addition, it is found that there is only a minor effect of surface modification on the compression strength after impact.