Optimized PCL/CNF bio-nanocomposites for medical bio-plotted applications: Rheological, structural, and thermomechanical aspects

Bioprinting 2023 Volume 36, Article e00311

The use of bioabsorbable and biodegradable composites in the medical field has experienced significant growth. Cellulose nanofibers (CNF) have been employed to reinforce medical-grade poly[ε-caprolactone], enhancing both its load-bearing capacity and stiffness compared to pure polycaprolactone PCL. The manufacturing process involved a series of steps applied to five different grades of PCL/CNF filaments. Initially, melt extrusion and pelletization were performed on the filament, followed by 3D bioplotting to create the specimens. The influence of CNF reinforcement on poly[ε-caprolactone] was evaluated through a range of tests, including rheological, thermomechanical, and in situ micromechanical assessments. To further characterize the samples, Micro-Computed Tomography and Scanning Electron Microscopy fractography were employed for the microstructural and morphological analyses, respectively. The mechanical properties of poly[ε-caprolactone]/CNF composites with 6 wt % CNF content exhibited a 23.8% increase in tensile strength and a 19.1% increase in flexural strength compared to the pure matrix, while also displaying minimal porosity.