Date of Award


Document Type


Degree Name

Bachelor of Science



First Advisor

Dr. Christine Helms


The aim of this study was to determine the role of entanglement in the mechanical properties of electrospun polycaprolactone (PCL) fibers. PCL is a useful polyester due to its favorable properties such as its biocompatibility and biodegradability. Multiple concentrations of PCL were dissolved in a 3:1 acetic to formic acid solvent. Fibers were formed using an electrospinning technique. Entanglement is a required parameter to produce fibers, thus the number of entanglements per polymer (ne) was calculated, as well as the corresponding concentrations. Smooth continuous fibers were found to form between 13 w/v% and 17 w/v%. Mechanical analysis, such as three-point bending and lateral manipulation, of the fibers was done using the Atomic Force Microscopy (AFM). The initial modulus of the electrospun fibers did not depend on polymer solution entanglement. However, when probed at higher strains, differences in the stress and strain behavior of individual fibers formed from varying concentrations were observed. Fibers formed from higher solution concentrations of PCL, or higher ne, were shown to extend to higher strains, which in turn increases the maximum amount of stress the fiber can withstand before rupture. All PCL fibers displayed strain-hardening behavior. These results indicate that entanglement plays a role in the mechanical properties of electrospun fibers at large strains.

Available for download on Thursday, May 08, 2025

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Chemistry Commons