Fabrication of polycaprolactone/polyvinyl alcohol green composite film by reinforcing extracted micro cellulose fibers for food packaging applications

Abstract This study presents an innovative strategy for sustainable food packaging by fabricating green composites composed of a polycaprolactone (PCL) and polyvinyl alcohol (PVA) blend reinforced with polyethylene oxide (PEO)‐modified cellulose microfibers (mCMFs) extracted from biowaste. A series of composites containing varying concentrations of mCMFs (1–3 wt%) were prepared using extrusion and injection molding. Remarkably, the incorporation of just 1 wt% mCMFs enhanced the mechanical properties by 49.15% compared to the PCL–PVA blend. Thermogravimetric analysis (TGA) revealed improved thermal stability, with the initial degradation temperature increasing from 343°C (PCL) and 209°C (PVA) to 384°C for the 1%mCMFs/PCL–PVA composite. Differential scanning calorimetry (DSC) also indicated enhanced thermal behavior, with the melting temperature rising from 68°C (PCL–PVA) to 72°C (1%mCMFs/PCL–PVA). SEM and FTIR analyses confirmed improved fiber–matrix adhesion and stronger hydrogen bonding interactions. Furthermore, density functional theory (DFT) calculations using Gaussian software theoretically validated these interactions by comparing hydrogen bond energies: 1504.53 kcal/mol for PEO‐modified cellulose, 763.35 kcal/mol for PCL–PVA, and a significantly higher value of 2201.23 kcal/mol for the 1%mCMFs/PCL–PVA composite. These results underscore the synergistic effect of PEO and cellulose in enhancing the performance of the PCL–PVA composite, offering a biodegradable, thermally stable, and mechanically robust material suitable for food packaging applications. Highlights PVA film improved thermal traits of PCL–PVA polymer blend. PEO‐modified CMFs enhanced matrix–filler compatibility. mCMFs reinforced PCL–PVA via extrusion/injection molding. mCMFs raised PCL–PVA composite strength by 49%.