Thermal-cold fatigue of continuous carbon fiber reinforced polyetheretherketone

Thermal-cold fatigue of continuous carbon fiber reinforced polyetheretherketone (PEEK) was studied in this paper. It was found that the fatigue depends on the interfacial structure of the composites. When a transcrystalline layer of PEEK is formed around the fiber, the composite elastic moduli increase with the increase of thermal-cold cycle time at beginning, and later tend to decrease. But the moduli almost remain unchanged in the case of PEEK spherulites appearing around the fiber in the composites. The distinct interfacial effects on the fatigue are considered to be related to the microstructural difference between PEEK transcrystalline and spherulites, which leads to the differences in thermal conductivity and rigidity.