Enhancing electrospun PET nanofiber yarns via thermal crystallization for artificial ligament applications

This study aims to develop an artificial ligament material by applying thermal crystallization techniques to electrospun polyethylene terephthalate (PET) nanofiber yarns, inspired by the hierarchical structure of ligaments and tendons at the microscopic level. We demonstrate that applying an appropriate thermal crystallization temperature to the nanofiber yarn significantly enhances the polymer's crystallinity, thereby greatly improving the tensile strength of the fibers without altering the yarn's structure. The crystallinity of the polymer fibers can be controlled by exposing them to specific temperatures, and it was observed that fibers subjected to optimal thermal crystallization exhibited a marked increase in crystallinity, achieving high tensile strength (∼83 MPa) without microstructural deformation. These results indicate that proper thermal crystallization can effectively enhance the tensile strength of polymer fibers. Finally, the study confirmed that fibers woven from thermally crystallized nanofiber yarns possess strong potential as artificial ligament materials.