Characterization and micromechanical testing of the interphase of aramid-reinforced epoxy composites

The properties of the interphase between Twaron* aramid fibres and polymer matrix systems can be optimized by a surface treatment process of the fibre s. The relation between this surface treatment, the resulting chemical and physical surface structure, as measured with XPS, IGC and SFM, and the adhe sion strength in fibre-epoxy systems, as measured with Raman spectroscopy a nd single-filament pull-out experiments, has been established and related t o the macromechanical data of real composites. The concept of local bond st rength was used and the fibre-epoxy failure mechanism investigated. (C) 200 1 Elsevier Science Ltd. All rights reserved.