Development of biodegradable laminate films derived from naturally occurring carbohydrate polymers

In recent years, co-extruded laminate films have become increasingly important for many applications, especially in the food industry, where they are mainly applied in the packaging of products such as fresh pasta, meats and cut vegetables to extend the shelf-life of the goods. Commercial multilayer films currently comprise a number of layers (3-9) of different polymers. In most applications, the outer layers consist of cheap, water barrier polymers with good mechanical properties (polyethylene [PE], polystyrene [PS]); the inner layers consist of more expensive materials, which offer good gas-barrier properties (polyvinylidene chloride [PVdC], polyethylene terephthalate [PET]). However, the existing products are not biodegradable. Such conventional plastics, manufactured from fossil fuels, not only consume non-renewable and finite resources, but also impact heavily on waste disposal. For this reason, BioComposites Centre is collaborating in the development of new laminate films for the production of food packaging. These new materials include laminates based on modified starch and polylactic acid (PLA), which are anticipated to present good water and gas-barrier properties, as well as easily extruded and processed, and eventually (bio)degraded at the end of the product life. (c) 2004 Elsevier Ltd. All rights reserved.