Formulation and Optimization of Carboxyl Methyl Starch/PVA/Kaolin Biocomposite Films for Sustainable Packaging Applications

Background and Objective: The use of synthetic polymers as packaging materials contributes to environmental pollution due to the accumulation of plastic waste after their usage. This study aimed to develop and optimize eco-friendly carboxyl methyl starch/PVA/kaolin composite films as a sustainable alternative to synthetic packaging, using response surface methodology. Materials and Methods: The biocomposite films were produced through the solution casting method using formulations obtained from the experimental design. The independent variables used in the formulations include: Carboxyl methyl starch (CMS) (2.0-5.0 g), poly (vinyl alcohol) (PVA) (0.0-3.0 g) and kaolin (0.00-0.22 g) while the responses of interest to achieve maximum properties were ultimate tensile strength (UTS), elongation at break (EB (%)) and water vapor permeability (WVP). Response surface methodology (RSM) a statistical tool based on central composite design (CCD) was employed to optimize the film compositions for best properties. The data obtained from the tensile mechanical and water vapour permeability test were analyzed statistically using standard methods, including linear regression and Analysis of Variance (ANOVA), to determine the significance of the results and correlations between variables. Results: The findings revealed that the combination of PVA and kaolin with CMS enhanced the tensile strength and barrier properties of the composite films. The optimal composite formulation, with 95.4% desirability, consisted of 3.33 g CMS, 2.39 g PVA and 0.22 g kaolin. The predicted optimal values for UTS, EB (%) and WVP were 5.71 MPa, 23.57% and 1.08 g/m² sPa, respectively. Conclusion: Based on data and information obtained from this study, it is clear that optimized CMS-based composite film can potentially serve as a sustainable solution in combating environmental problems emanating from the synthetic plastics.