A study of pure hydrolysis of carbon fibre reinforced polyamide 6 composites tested under mode I loading

• Published in: Composites. Part A, Applied science and manufacturing Applied science and manufacturing, 2022-01, Vol.152 (Part A), p.106719, Article 106719
• Main Authors: Arhant, Mael, Lolive, Eric, Bonnemains, Thomas, Davies, Peter
• Format: Article
• Language: English
• Subjects: Arrhenius; Hydrolysis; Mode I fracture; Molar mass; Sciences of the Universe; Thermoplastic composites
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2021.106719

•A critical molar mass was identified for the first time on a long carbon fibre reinforced composite.•Even after extensive ageing degradation, the fracture toughness of C/PA6 composite is similar to those of unaged C/Epoxy composites.•It is possible to predict the long term fracture behaviour of C/PA6 using an Arrhenius approach. This paper focuses on the durability of carbon/polyamide 6 thermoplastic composites subjected to hydrolytic aging and tested under mode I static crack growth loading. In this study, aging was performed at temperatures ranging from 100 to 140 °C for durations up to 3 months in oxygen-free water. Results show that following wet aging the fracture toughness (energy release rate) decreases significantly, from an unaged value of 3.4 kJ/m2 down to values below 1 kJ/m2 after extensive degradation. This decrease was associated with a change from ductile to brittle behaviour, which allowed a critical molar mass M’c, to be determined for the first time on long carbon fibre reinforced composites.