Fibre-reinforced composites with tailored interphases using PPE/epoxy blends as a matrix system

In this study poly(2,6-dimethyl-1,4-phenylene ether) (PPE) is introduced as a ductile thermoplastic matrix for high-performance carbon fibre-reinforced composites by using epoxy resin as a reactive solvent. An interesting feature of this reactive composite processing route is that the epoxy resin acts not only as an effective solvent, lowering the viscosity and processing temperature of the polymer matrix, but also provides an essential structural part of the final composite material. Upon curing and subsequent phase separation, a morphology of epoxy-coated fibres in a nearly pure PPE matrix results. This phenomenon is not only of great importance with respect to the possibility to drastically improve the adhesion between the fibres and the thermoplastic matrix, but also creates the challenge to tailor the mechanical properties of these in situ formed interlayers by changing the chemistry of the epoxy phase