Effect of freeze-thaw cycling on the mechanical properties of continuous carbon fiber-reinforced polyamide 6 composites

• Published in: Polymer testing 2022-10, Vol.114, p.107704, Article 107704
• Main Authors: Lei, Yongpeng, Kang, Zhenhang, Zhang, Jifeng, Sun, Yiliang, Zhang, Boming
• Format: Article
• Language: English
• Subjects: Continuous carbon fiber-reinforced polyamide 6 composites; Freeze-thaw cycling; Tensile properties
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2022.107704

This paper deals with the effects of different freeze-thaw cycling environments on the mechanical properties, dimensional stability, and water absorption behaviors of continuous carbon fiber reinforced polyamide 6 composites (CF/PA6). In a nominally dry state, freeze-thaw (FT) exposure can slightly increase the mechanical properties due to the elimination of residual stress. However, FT exposure in a water immersion environment causes a linear decrease in transverse tensile properties and flexural properties and an exponential decrease exposure in water immersion environment. This difference in degradation rate can be attributed to the varying water content, and the relationship between retention rate of mechanical properties and FT cycles was further developed to predict its long-term aging performance. In addition, water absorption behaviors, dimensional measurement, and micro-characterization were also applied to analyze the mechanism of mechanical properties degradation. •The evolution of mechanical properties for CF/PA6 composites under different aging environments is observed.•The relationship between retention rate of mechanical properties and FT cycles is determined.•The moisture swelling strain is about five times that of the thermal swelling strain.•The damage mechanisms can be summarized in two ways: plasticization and moisture swelling incompatibility.