Effects of vermiculite clay on the physical, chemical, and mechanical properties of biocomposites made from babaçu coconut mesocarp starch and alginate

Biopolymers are natural materials derived from proteins, polysaccharides, lipids, or their derivatives, used in biodegradable packaging production. The addition of vermiculite clay can improve mechanical properties, enhance consistency, and thermal stability, broadening biocomposites' applications. This study investigates the effect of varying starch, alginate, vermiculite clay, and plasticizer concentrations on properties like moisture, solubility, water vapor permeability (WVP), and mechanical traits (tensile strength, elongation, and Young’s modulus). Fifteen tests were performed with variations in vermiculite clay concentrations, as well as variations in the amount of material placed on the plate. Results showed that films with higher vermiculite clay content had lower moisture (20.64% to 24.61%) and higher solubility. WVP increased with film thickness. Regarding mechanical properties, the 3 g vermiculite clay formulation showed better resistance and flexibility. Tensile strength ranged from 2.26 to 4.84 MPa, with elongation between 9.27% and 20.47%. These values suggest that the formulation can withstand moderate stress before failure. Young's modulus, ranging from 13.65 to 52.27 MPa, reflects a balance between stiffness and flexibility, making it ideal for applications requiring mechanical strength combined with flexibility.