Abstract. This paper investigates a carbon fibre-reinforced polyetherketoneketone (CF-PEKK) thermoplastic composite used for low-temperature applications like hydrogen tank applications. The degree of crystallinity of the prepreg as received first and then consolidated after hot press has been investigated. The melting temperature and glass transition, as well as the melting enthalpy and degree of crystallinity, were also studied by DSC (differential scanning calorimetry). The fibre volume fraction and void content after consolidation have been measured by acid digestion and an optical microscopy image analysis. Thermomechanical analysis (TMA) was also used in order the coefficients of thermal expansion (CTE) to be determined. Tensile and compressive Dynamic Mechanical Analysis (DMA)test were performed. Storage modulus, loss modulus, and Tan δ relationship have thus been analysed. Multifrequency DMA experiments have been conducted in order to create the master curve thanks to the time-temperature superposition (TTS).