## 1 Introduction  
Plastic serves as an unavoidable and ubiquitous material in packaging. The packaging industry is responsible for 40% of the total plastic usage globally [1]. This extensive reliance on plastics has led to an unprecedented environmental crisis. Due to their resistance to natural degradation, plastics accumulate massively in oceans, rivers, and soils [2, 3]. This accumulation severely impacts ecosystems and wildlife and poses potential risks to human health [4]. In the face of this problem, the search for sustainable alternatives to conventional plastics is imperative, balancing long-term properties with appropriate end-of-life management [5]. The development of biodegradable and compostable materials, as well as the implementation of circular economy strategies, represent promising approaches to mitigate the environmental impact of plastics [6, 7, 8]. These solutions not only have the potential to reduce waste accumulation but also to decrease reliance on non-renewable fossil resources and promote more responsible and sustainable practices in industry and consumption [9,10]. One of the most promising alternatives is thermoplastic starch (TPS). Derived from renewable resources such as corn, potatoes, and other starch-rich plants, TPS is an attractive candidate due to its low cost and abundant availability [11,12]. Thermoplastic starch can be processed using conventional plastic manufacturing techniques, facilitating its integration into existing production systems [13]. Additionally, TPS is biodegradable, reducing the environmental footprint associated with plastic waste [14,15]. Thermoplastic starch (TPS) is created by disrupting the granular structure of starch through the application of heat and mechanical shear in the presence of plasticizers such as water and glycerol. This process produces a material with properties akin to traditional thermoplastics but with the added advantages of being derived from renewable sources and fully biodegradable under suitable conditions [16,17]. These attributes make TPS a promising alternative for reducing the environmental impact of packaging materials [18]. However, TPS alone has certain limitations regarding its mechanical properties and sensitivity to moisture, which restrict its use in more demanding applications [19]. To overcome these limitations, it is common to blend thermoplastic starch with other biodegradable polymers, especially polyesters, which provide the necessary functionality. Biodegradable polyesters such as polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene succinate (PBS), and polyethylene adipate-co-terephthalate (PBAT) are some of the most common options for improving the properties of TPS [20,21]. Polybutylene adipate-co-terephthalate (PBAT) is an aliphatic-aromatic polyester that is highly flexible and resistant. Mixing PBAT with TPS results in a material that combines the flexibility and durability of PBAT with the biodegradability of TPS, making it an ideal choice for packaging films and other flexible products [22]. Polybutylene succinate (PBS) is another biodegradable polyester known for its excellent processability and heat resistance. Although the melting temperature of PBS is between 90 \({}^{\circ}\)C and 120 \({}^{\circ}\)C, it demonstrates stability under medium-temperature conditions due to its inherent molecular structure, which provides a balance between crystallinity and flexibility. This characteristic allows PBS to maintain its performance in applications where moderate thermal resistance is required [23]. The combination of PBS with TPS can produce materials with balanced mechanical properties and higher thermal stability, which is beneficial for applications requiring resistance to higher temperatures [24]. The blending of TPS with these polyesters is typically performed by extrusion and compounding, where starch and polymers are melted and mixed at high temperatures to form a homogeneous material.