Bio-based films prepared with by-products and wastes: environmental assessment

Considerable interest in bio-based films has been renewed due to their potential use in packaging industries. Polymers from biomass receive increasing interest as potential substitutes for certain conventional polymers since they are derived from renewable sources and can be biodegradable. However, the life cycle assessment of biofilms has not been widely reported in the literature. In this context, this paper discusses the environmental assessment of bio-based films based on agro-industrial by-products and marine residues, providing added value to these wastes. The materials employed to prepare the bio-based films were soy protein obtained as by-product of soy oil industry, chitosan obtained from the skeleton of crustaceans, and agar obtained from marine seaweeds. The results showed that manufacture is the most contaminant stage for chitosan and agar films, whereas the extraction of raw materials is the stage with the highest environmental burden for soy protein films. In addition, soybeans cultivation contributes to the environmental burden in land use category due to the use of glycerol, considered as by-product from biodiesel production, as plasticizer. However, the end of life stage is the least pollutant phase for bio-based films due to the fact that their biodegradable nature allows composting as the end of life scenario, providing environmental benefits. The present study allows identifying the most pollutant phases of the life cycle for biofilms from different resources, which is the first step prior to the analysis of the changes needed during the design of products and processes to minimize negative impacts in the environment. (C) 2013 Elsevier Ltd. All rights reserved.