Fabrication of Nanocomposite Films Composed of Starch/Gelatin/Clay via Casting Method and Analyzing Their Characteristics Using RSM

In this study, the nanocomposite films composed of starch/gelatin/nano clay were fabricated and their physiomechanical properties were investigated. The experimental design was done via the RSM method with Design Expert 7.0 software. The gelatin/starch weight ratio and the nanoclay weight percent were selected as independent variables and the tensile strength, Young modulus, elongation at break, and contact angles as dependent ones. The mathematical equations that identify the relationship between the dependent and independent variables were obtained. The results demonstrated that the tensile strength and modulus and the hydrophobicity of the surfacewere increased as nanoclay increased and the portion of gelatin decreased while the elongation at break showed reverse behavior. In the following, the optimization was done and the optimized values for gelatin/starch and nanoclay weight, percent were introduced to have the maximum tensile strength and minimum hydrophilicity. The optimum nanocomposites were fabricated and analyzed via FT-IR, SEM, XRD, and biodegradability tests. The obtained results showed that the nanoclay sheets were intercalated and proper dispersion of nanosheets in the polymeric matrix achieved. The nanocomposite films showed proper degradability and their weight was decreased by 40% after 6 weeks. Overall, this research work confirmed the proper potential of starch/gelatin/nanoclay nanocomposites as biodegradable food packaging films.