Interphase study of thermoplastic modified epoxy matrix composites: Phase behaviour around a single fibre influenced by heating rate and surface treatment

This paper presents an investigation of the interphase morphology of a polyether sulphone (PES) modified triglycidyl-amino-phenol (TGAP) epoxy system reinforced with single carbon and glass fibres. The effect of heating rate of the cure and fibre surface treatment (calcination desizing and silane treatment with a γ-glycidoxypropyl-trimethoxysilane coupling agent) was studied. The phase morphology was investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). It was noted that the domain size and the concentration of the dispersed PES-rich particle phases in the closest proximity of single fibres increase with the increase of heating rate. In comparison with calcination desizing, silane treatment leads to higher concentration of the dispersed PES-rich particle phases in the closest proximity of the reinforcement.