Evaluation of the physical–chemical properties of the blend of arrowroot starch and cactus mucilage

Abstract The replacement of these polymers by biodegradable ones is a promising alternative to mitigate the environmental problems caused by these materials. The mixture of biopolymers obtained from arrowroot starch (ST) and cactus mucilage (MU) may have its properties enhanced for the production of food packaging. In this study, it was used solution casting technique to develop blends of ST and MU in different compositions, analyzing their thermal, mechanical, and physical–chemical properties. Through a principal component analysis, it was verified that the technique used to mix the polymers was satisfactory. A reduction in the crystallinity of the polymer blends was noted in all formulations, especially when compared to films made only from arrowroot starch or cactus mucilage. This alteration means that the materials have lower stiffness. Water vapor permeability was shown to be lower in the blend with the highest starch concentration. The films with a 75/25 ST/MU formulation exhibited higher elongation at break values, while no significant changes in tensile strength were observed when compared to other concentrations, except for the pure ST films, which showed lower tensile strength and greater elongation at break. For the thermogravimetric analysis, comparing between the blends, an increase in thermal stability was perceived for the formulation ST/MU 75/25. Based on these results, the evaluated blends show potential for use as food packaging in short‐term applications. Highlights Development of arrowroot starch blends and cactus mucilage. Polymer blends showed lower crystallinity values. Increased starch concentration reduced water vapor permeability. The ST/MU 75/25 blend had better tensile strength and specific deformation. Starch addition improved thermal stability in blend formulations.