Low temperature hot melt extrusion of polycaprolactone/polyethylene oxide/chitosan ternary blends for biocompatible implantable device development

• LT-HME enables the successful processing of PCL, PEO, and Cs under reduced thermal conditions, as evidenced by decreased melt viscosity and torque during extrusion. • Cs reduced PCL crystallinity while PEO incorporation moderated this effect by enhancing PCL/Cs compatibility and Cs dispersion at PCL/PEO interface • Implications for drug release performance and biorelevance of the fabricated PCL/PEO/Cs blends remain hypothetical and require further experimental validation. Rising demand for biomedical devices requires manufacturing approaches suitable for processing thermally-sensitive materials. Hot-melt extrusion may cause thermal degradation of polymers and bioactives. This study examines low-temperature hot-melt extrusion (LT-HME) as an alternative processing method for blends of polycaprolactone, polyethylene oxide, and chitosan (PCL/PEO/Cs), fabricated using a twin-screw extruder under reduced temperatures. Extrudates were characterised using scanning electron microscopy, gel permeation chromatography, Fourier transform infrared spectroscopy, differential scanning calorimetry, and rheology. LT-HME enabled melt-blending with reduced torque and no chemical degradation or adverse intermolecular interactions. Thermal analysis revealed a modest reduction in PCL melting temperature and crystallinity across blended systems without evidence of complete amorphisation miscibility. Composition-dependent morphological variations were demonstrated, including phase separation and void formation in blends containing PEO and/or Cs, with ternary blends exhibiting comparatively improved structural uniformity and interfacial adhesion relative to binary blends. Rheological measurements showed enhancements in storage and loss moduli and complex viscosity, particularly for the A3 ternary composition, indicating altered melt behaviour during extrusion. The results provide an initial insight into the processing behaviour of PCL/PEO/Cs ternary blends via LT-HME. This supports further investigation into multi-component polymer systems including optimising formulation parameters, robust structural validation and biocompatibility studies for potential biomedical applications.