Correlation of the crystalline structure, moisture content, texture and aging-induced degradation of polyamide 5.10 using wide-angle x-ray scattering analysis

• Moisture-induced signal loss in WAXS was found to be fully reversible after re-drying • A discrepancy between WAXS and DSC revealed complex crystallinity-related change • Hydrothermal aging showed interplay between plasticization, annealing, and structure • Moisture effects were resolved across crystalline and amorphous regions of PA5.10 This study provides a detailed analysis of the crystalline structure of polyamide 5.10 (PA5.10) and determines the effects of hydrothermal aging on its moisture content, crystallinity, and texture. Using wide-angle X-ray scattering (WAXS), the investigation revealed insights into both the amorphous boundary layer and the semi-crystalline core, with a Python script based on Bragg ’s law enabling precise identification of crystalline phase planes. Gaussian fitting of crystalline peaks further refined the structural understanding. The effects of experimental parameters on WAXS measurements were examined to identify additional factors influencing PA5.10. Hydrothermal aging led to notable changes, including increased moisture absorption, volume expansion, enhanced crystallinity, and shifts in molecular structure and crystalline morphology. WAXS showed that moisture-induced scattering reduced intensity, which was reversible upon re-drying. Despite an increase in crystallinity observed by DSC, WAXS did not capture a corresponding shift, likely due to the combined effects of residual moisture and annealing processes. Overall, this study enhances the understanding of PA5.10′s crystalline behavior under hydrothermal exposure and provides a basis for future investigations into its aging processes and structural evolution. These findings contribute to a broader understanding of the long-term degradation mechanisms and stability of bio-based polyamides under hydrothermal and humid conditions. Moreover, the insights gained are relevant for predicting material performance in moisture-sensitive applications and can inform the development of stabilization strategies for hygroscopic polymers.