Flexible Food Packaging Using Polymers from Biomass

The use of polymers from biomass in the production of flexible packaging is an important challenge to give an answer to both the reduction of oil-derived materials and the increase of waste production. Oil-derived materials are now employed in recyclable packaging, but, although the management of waste recycling is improving, it cannot allow the complete mechanical recycling of the plastic fraction. It would be important to optimize the system by replacing packaging difficult to be recyclable, such as multi-layer flexible packaging mainly based on the use of polyolefines, with alternative packaging consisting of biodegradable materials, thus managing its disposal by considering composting. In the present paper, a classification of polymeric materials available from biomass for flexible packaging is reported. Moreover, the biodegradable and renewable materials investigated or yet employed in this sector are described. In addition, some insights on the actual production of flexible packaging is given, to describe also what technical specification the polymers from biomass should have to replace commodities. Finally, the perspectives in the field of flexible packaging for polymers from biomass are discussed. 1. Polymeric Materials from Biomass As material scientists, we often need to study and select the best material for a specific application. In many cases, especially for applications requiring the combination of lightness and resistance, polymeric materials are quite interesting, as well as blends or composites obtained by using them blended with other polymers or with inorganic or organic fillers. In fact, polymers, with respect to other materials, show a higher versatility due to the possibility of modulating their macromolecular structure by controlling the industrial synthesis in order to achieve specific final properties. The structural materials selected by nature in plants and animals are based on polymers too. The main structural polymer for plants is cellulose, a polyether, which is the polymer of D-glucose having each repeating unit linked to the following one by a β(1-4)-linkage. The main structural polymers for animals are proteins, characterized by a polyamide structure. In general, polymers can be natural, artificial or synthetic (Table 1). An example of a natural polymer is cellulose, contained in paper or cotton fabric; among