Improvement of Mechanical Properties of PCL Nanofibers Through Thermo‐Compression Process

ABSTRACT Recently, polymeric nanofibers have been widely used in various fields, including electronics and optics, filtration media, and bioengineering. Electrospinning is one of the most common nanofiber fabrication methods due to its simple processing principle, straightforward equipment, and broad material applicability. Electrospun nanofibers typically form nonwoven structures with high surface‐area‐to‐volume ratios and high porosity; however, their applications are often limited by poor mechanical properties and structural instability caused by weak interfiber connectivity. Several posttreatment methods, including solvent vapor annealing and thermo‐compression, have been employed to improve the mechanical properties of electrospun nanofibers. Among them, thermo‐compression is particularly attractive because it requires simple processing and avoids the use of harmful solvents. Nevertheless, systematic parametric studies incorporating a theoretical interpretation remain limited. In this study, the effects of thermo‐compression parameters—including compression duration, temperature, and pressure—on the mechanical properties of electrospun nanofibers were investigated. The time‐dependent deformation behavior of electrospun nanofibers during thermo‐compression was interpreted using the Deborah number to qualitatively relate the process parameters to interfiber connectivity. The results show that mechanical properties were enhanced under lower Deborah number conditions, while the overall nanofibrous structure was well preserved.