PEG‐Mediated Aqueous Processing of Cellulose Nanofiber/Polycaprolactone Composites

This study aimed to develop and characterize Cellulose Nanofiber/Polycaprolactone (CNF/PCL) composites using a low‐temperature, organic‐solvent‐free aqueous processing method. The composites were prepared by gradually incorporating a hydrated CNF/PEG gel into PCL melted at 75°C through repeated rolling and folding. FTIR and DSC results were consistent with physical blending, without evidence of new chemical bonding or additional thermal transitions. CNF incorporation significantly improved tensile performance: all composite formulations exhibited tensile strengths above 30 MPa. The highest value, approximately 35 MPa, was obtained for the sample containing 0.5 wt% CNF, compared with about 19 MPa for neat PCL. The composites also exhibited Young's moduli of approximately 500–600 MPa. Porosity increased from approximately 20% for neat PCL to more than 42% for the composite containing 99.01 wt% PCL and 0.99 wt% CNF. SEM showed distributed fibrillar features without prominent CNF‐rich agglomerates. Surface roughness remained within a similar submicrometer range, while skewness and kurtosis were more sensitive to localized surface variation caused by changes in composite formulation. These findings demonstrate that aqueous rolling and folding can produce mechanically reinforced CNF/PCL composites with improved tensile properties for potential biomedical applications.