Influence of Long‐Term Thermo‐Oxidative Treatment on the Properties of Carbon Fiber/Polycarbonate Thermoplastic Composites

ABSTRACT The effect of the thermo‐oxidative environment on the properties of carbon fiber/polycarbonate thermoplastic composites was investigated in this research. The degradation of performance properties and reduced durability are key concerns for carbon fiber thermoplastic composites under challenging and varying environmental conditions, especially in thermo‐oxidative environments. This study focuses on the flexural and thermal properties of carbon fiber reinforced polycarbonate composites (CF/PC). The CF/PC composites were subjected to two distinct temperatures (100°C and 180°C) for extended periods. Negligible weight change was observed at 100°C, whereas 180°C led to continuous loss over time. The deterioration of mechanical performance was assessed through continuous monitoring of changes in flexural modulus and strength throughout the thermo‐oxidative treatment period. At 180°C, flexural strength dropped sharply, retaining just 12.7% and 5.9% after 2160 and 2640 h; in contrast, changes at 100°C were slight. This difference is likely due to the gradual degradation of the PC matrix and failure at the interface. In terms of thermal performance, the unaged material exhibited a weight loss percentage of 23.08%. At an aging temperature of 100°C, the thermal stability of the material remained virtually unchanged. However, at 180°C, both the initial decomposition temperature and the temperature corresponding to the maximum weight loss rate progressively decreased. This significant reduction in thermal stability was primarily attributed to the cleavage of ester bonds and the detachment of terminal groups within the PC molecular chains.