Electrospun Polylactide-Poly(ε-Caprolactone) Fibers: Structure Characterization and Segmental Dynamic Response

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Electrospun ultrathin fibers are crucial for various applications.
• Understanding the molecular interactions in polymer blends is essential for tailoring material properties.
• Polylactide (PLA) and poly(ε-caprolactone) (PCL) are biocompatible polymers with distinct characteristics.

Purpose of the Study:

• To investigate the structural and dynamic properties of electrospun PLA/PCL blend fibers.
• To determine the effect of varying PLA/PCL ratios on polymer blend characteristics.
• To identify specific blend compositions that exhibit phase inversion.

Main Methods:

• Fabrication of electrospun fibers using various PLA/PCL ratios (0/100 to 100/0).
• Thermal analysis using Differential Scanning Calorimetry (DSC).
• Electron Spin Resonance (ESR) spectroscopy with a stable TEMPO radical probe.

Main Results:

• Significant changes in PLA/PCL crystallinity, segment mobility, and TEMPO probe sorption were observed upon blending.
• The activation energy of TEMPO radical rotation in intercrystalline regions was evaluated.
• A characteristic composition range (50/50 to 30/70% PLA/PCL) showed an inversion transition of PLA from a dispersive medium to a discrete phase.

Conclusions:

• The ratio of PLA to PCL significantly influences the structural and dynamic properties of the blend fibers at a molecular level.
• The study provides insights into the phase behavior and molecular dynamics of PLA/PCL blends.
• Findings are critical for designing advanced PLA/PCL based materials with controlled properties.