Biopolymer Films and Composite Coatings: Applications

Facing the problem of excessive use of conventional petroleum-based plastic materials in a wide range of daily life applications is undoubtedly an urgent global issue. Researchers and organizations have driven much effort to develop novel materials such as coatings and films based on biopolymers which have emerged as a viable way to replace, at least partially, synthetic products. Biopolymers, like polysaccharides and proteins, can be obtained from marine or agro-industrial resources and also by food processing waste and by-products, which contributes to sustainability and a circular economy. Biopolymer films are pre-formed structures produced by solvent casting and extrusion procedures, while coatings are formed directly on the product surface by spraying, dipping, or spreading techniques. To enhance films and coatings properties, strategies including chemical modification, cross-linking, plasticizers addition, use of fibers and nano reinforcing materials, and blending of different biopolymers have been adopted. Although there is still much to be done in terms of mechanical and water barriers properties and large-scale processability, the incorporation of active agents into the biopolymer matrix, mainly natural antimicrobials and antioxidants, vitamins, nutrients, and growth factors, has emerged as one of the significant advantages in the design of novel functional materials. These active ingredients can prolong shelf life and provide many other additional characteristics of the final products. This chapter intends to cover the relevance and recent advances in biopolymer films and composite coatings, highlighting their applications in different sectors such as food packaging, medicine, textile, and agriculture.