Thermal and Water Uptake Behavior of Copernicia prunifera Leaf Extract/PEG-Loaded Cellulose Acetate

Polymers derived from lignocellulosic sources have gained increasing attention in recent years due to their environmental sustainability, biocompatibility, and renewability. In this study, thermal properties and water uptake behavior of cellulose acetate loaded with PEG1500 and Copernicia prunifera leaf extract were investigated. A twin-screw extruder and hot press moulding was used in the manufacturing process. An ATR-FTIR analysis was performed to identify the functional groups within the structure and to assess possible chemical changes. Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) analyses were performed to determine the material’s thermal properties. Subsequently, water uptake test was performed. The FTIR analysis results showed the characteristic peaks of the raw materials as expected, and no new functional groups were formed among the components. TGA results revealed that adding PEG1500 decreased the onset temperature of thermal degradation, whereas adding extract increased it by 20–30 °C. Similar behaviour was also observed in the DSC analysis, the glass transition temperature of composites increased by 5–10 °C with the addition of the extract. Additionally, its wax-like structure strengthened the hydrophobic character of the matrix by reducing its water uptake capacity. The water uptake rate of PEG-loaded cellulose acetate (w/w;10/90) decreased by 6% with the extract (5%) addition. The findings indicate that Copernicia prunifera leaf extract compensated for the negative properties of PEG1500 and was found to be suitable for use together in a cellulose acetate matrix. Using natural and biodegradable ingredients in composite systems can create an eco-friendly alternative to plastic, reducing the ecological footprint and supporting the circular economy.