## 1 Introduction  
Plastic pollution is currently a major environmental problem, with millions of tons of plastic waste accumulating worldwide [1]. Polymers derived from petroleum-based resources have detrimental effects on ecosystems, prompting scientists and industries to seek methods to mitigate their harmful environmental impact. One solution that has gained attention in recent years is the substitution of conventional polymer products with biobased materials derived from renewable resources [2]. Among these resources, agricultural waste has emerged as a valuable feedstock for producing sustainable materials. Every year, a substantial quantity of agricultural waste is generated globally. Repurposing this waste is a promising approach to reduce environmental concerns while promoting a circular economy by converting waste into valuable resources [3, 4]. Potato peel waste (PW) is a major agricultural byproduct, as potatoes are the world's fourth most important food crop after rice, wheat, and maize [5]. Beyond its common use as a dietary staple, potatoes are widely utilized in various industries, including the production of potato chips, French fries, and starch, leading to the generation of a significant amount of industrial waste [6]. PW is rich in starch, cellulose, pectin, and bioactive compounds such as proteins, polyphenols, and glycoalkaloids. This composition has attracted extensive research for its valorization potential in various domains, including the extraction of thermoplastic starch and the production of biocomposites and packaging materials [7; 8], the isolation of bioactive compounds and antioxidants [9; 10], and the extraction of nanoparticles, such as starch and cellulose nanoparticles [11; 12; 13]. Potato waste, a zero-value and abundant biomass, has gained attention as a promising resource for biopolymer production, particularly for film formation intended to replace conventional packaging materials. However, this material has certain limitations. Potato peels are primarily composed of starch, followed by cellulose as the second major component [14]. The high starch content imposes several drawbacks on PW, including insufficient mechanical properties and high moisture sensitivity [15]. To enhance the performance of starch-based matrices, various strategies have been employed, such as blending with polymers that exhibit superior characteristics [16], as well as chemical modification and crosslinking [17]. One of the polymers with more promising features to modify the starch-based compounds is sodium alginate. Sodium alginate (SA) is a linear polysaccharide primarily extracted from the cell walls of brown seaweeds or produced by certain bacterial species, such as Pseudomonas aeruginosa. It is a copolymer composed of \(\beta\)-D-mannuronic acid (M) and \(\alpha\)-L-guluronic acid (G) units arranged in different sequences [18]. The block configuration plays a crucial role in alginate's physicochemical behavior and its ability to form gel networks upon interaction with multivalent cations. SA is a versatile polymer widely utilized in the food industry, agriculture, and biomedical and cosmetic applications due to its favorable properties, including non-toxicity, excellent film-forming ability, effective thickening, and renewability [18]. The molecular weight of SA is a key factor influencing its behavior in film-forming systems. Higher molecular weight typically results in longer polymer chains, which enhance film cohesion, viscosity, and mechanical strength through greater chain entanglement and enhanced hydrogen bonding. Several studies have incorporated sodium alginate into starch-based matrices to improve mechanical properties or reduce moisture sensitivity [19; 20; 21]. Plasticizers are small molecules added to polymers to enhance their flexibility and reduce brittleness. They work by reducing the intermolecular forces between polymer chains, which increases polymer chain mobility and lowers the glass transition temperature (Tg).