Temperature dependence of thermal, physical, and mechanical properties of C/PA6 thermoplastic composite: Comprehensive insights

Thermoplastic composites are widely adopted for their recyclability, rapid processing, high toughness, and impact resistance. However, comprehensive temperature-dependent datasets for accurate process modeling, along with an understanding of how polymer transition temperatures and associated molecular mobility govern the evolution of macroscopic properties, remain limited. This study presents the temperature-dependent thermal, physical, and mechanical behavior of unidirectional carbon fiber-reinforced polyamide 6 (CF/PA6) composite tape. Through experimental characterization, the relationships between polymer transition temperatures, matrix molecular mobility, and the resulting variations in material properties are established. The results reveal that the specific heat capacity, thermal expansion, density, and thermal transport properties evolve with temperature in response to changes in molecular mobility near the glass transition and melting temperatures of the polymer matrix. Mechanical testing demonstrates a gradual reduction in longitudinal properties, with fiber reinforcement continuing to provide structural support, in contrast to the pronounced temperature sensitivity and drastic decline observed in transverse and shear properties as the matrix softens. Therefore, this study provides a critical dataset for modeling and simulation efforts and offer essential insights into how polymer transition temperatures and associated molecular mobility govern the evolution of macroscopic properties.