Interphase compatibilization of high modulus pitch-based carbon fibre with high performance thermoplastic for adhesion promotion

摘要

Replacing thermoset by thermoplastic is a major research area in aeronautic industries. Polyetheretherketone (PEEK) is one of the most promising high performance thermoplastics able to fit with the atmosphere and space harsh conditions. The interphase properties investigation for the development of new composite materials by the use of innovative technologies and methodologies is a field of continuous progress . In this context, the major challenge concerns the compatibilization between PEEK-matrix and the carbon fibres. This is particularly the case during the shaping process of these composites due to (i) the commercial sizing inherent thermal degradation and therefore the difficulty to choose a suitable sizing chemistry, and (ii) the relative fibre surface low-reactivity. Thus, this study is related to the fibre/matrix interphase compatilization of this composite with a focus on the fibre surface reactivity and PEEK properties at the vicinity of the fibre. An innovative methodology was used to modify the fibre surface. To this end, we developed a versatile procedure able to quickly modify fibre surface for the development of eco-friendly adhesion promoters. For this purpose, we use an alternative method based on the so called "Layer-by- Layer" (LbL) technique allowing to prepare a coating based on the coalescence and the intermixing of complexes with thermoplastic polymer. This work is focused (i) on the carbon surfaces characterization and on its surface activation performed by atmospheric plasma pre- treatments, and (ii) on surface water-based sizing formulation treatments. The mechanical performance of composites and resulting interphase properties were measured. Its influence on interphase properties (iii) was identified by a careful multiphysical characterization to get quantitative information about the adhesion mechanisms.