Vol. 6, Issue 1, Part B (2024)

Polymeric materials are extensively utilized worldwide today. However, their recalcitrant nature and subsequent accumulation in the environment have led to various problems. There is a strong demand for the replacement of non-biodegradable polymers with biodegradable ones in specific sectors such as food packaging and medical devices, where recycling is not recommended. Biodegradable polymers can be categorized as natural-based materials and synthetic polymers. Polysaccharides and other essential macromolecules such as proteins belong to natural-based materials. This paper focuses on their application in food and cosmetic packaging, as well as solar energy. While each polymer presents specific properties, they also have limitations that prevent them from meeting the diverse performance requirements for packaging materials. Consequently, multilayer structures are commonly used to overcome specific disadvantages such as high cost, low barrier, and mechanical properties.

Polymers like starch and polyvinyl alcohol (PVA) can offer mechanical properties at low cost, while barrier polymers such as polyamides and ethylene vinyl alcohol can provide protection against gases, flavours, and odours within the packaging. However, the main drawback of these multilayer packages is their challenging recycling and reprocessing into new products. The exponential increase in the production and use of packages globally exacerbates the waste disposal problem. The growing interest in the environmental impact of discarded materials necessitates thermoplastic polymers that can be melted and reused as raw materials for new applications. An alternative strategy to enhance the physical properties (e.g., mechanical, thermal, degradation, barrier, etc.) of traditional polymeric systems is the incorporation of inorganic materials at the nanometre level. Additionally, chemical functionalization of such materials using active molecules with specific properties can impart new functionalities to the polymers. Other interesting prospects concern specific applications such as controlled release.

Starch, commonly extracted from wheat, rice, corn, and potato, is widely available and cost-effective, making it one of the most accepted biopolymers. Starch can be blended with other materials in proportions ranging from 30% to 80% depending on its application. Biodegradable polymers like PVA (Polyvinyl Alcohol) are commonly used as copolymers. Starch-based films are employed either as monolayers or in combination with barrier films as laminates for packaging applications. The main criterion determining the use of these biopolymers in food packaging is their potential for migration.