Temperature-Induced Effects on Wet-Spun Artificial Spider Silk Fibers

Abstract

Silk-based materials are sought after across various industries due to their remarkable properties, including high strength and flexibility. However, their practical application depends largely on how well these properties are maintained under different environmental conditions. Despite significant advancements in the large-scale production of artificial silk fibers, the effects of temperature on their mechanical behavior are understudied. In this study, the mechanical properties of artificial spider silk fibers between −80 and +120 °C are examined and compared to both synthetic and natural silk fibers. The findings reveal that artificial silk fibers maintain their strength up to +120 °C, though the strain at break slightly decreases, remaining above 60%. At −80 °C, the fibers exhibit increased strength, but the strain at break is reduced. While these artificial fibers closely mimic the behavior of natural silk, they show a noticeable reduction in extensibility at low temperatures. Complementing experimental data, differential scanning calorimetry, and thermogravimetric analysis are also conducted, proposing a simple physical model to explain the observed temperature-induced softening. Encouragingly, the degradation temperature of artificial silk is comparable to that of native silkworm and spider silk. This study underscores the importance of enhancing the mechanical robustness of artificial silk to expand its applications.