Degradability and sustainability of nanocomposites based on polylactic acid and chitin nano fibrils

Plastic food packaging materials currently in use are hardly recyclable and very often post consume plastic packaging is directed to incineration or landfill. Use of bio-recyclable plastic will have positive effect on environment, and is gaining importance in particular for the production of active packaging, where a longer shelf-life of the packed food, coupled with improved sustainability can justify the higher cost of biodegradable polymers versus current petro based polymers used in packaging. Among other biodegradable polymers polylactic acid (PLA) has attracted researcher and industries attention for the production of plastic food packaging. In the present contribute we report a study to evaluate the degradability in compost of some representative examples of materials prepared with PLA and chitin nano-fibrils (NC). Since blending a biodegradable polymer with an active compound might hinder the compost ability of the materials produced, it is important to perform test of degradability on innovative materials even if based on biobased and biodegradable components. As well the production of bio-based, biodegradable materials when based on innovative processes, may present several steps that may have a negative effect on sustainability being not optimised in yield, energy consumption and proper valorization of each stream generated in the process. A life cycle assessment study is very important to spot the critical steps in the process and propose corrective actions in the production cycle in order to make the final material more sustainable. The materials based on PLA and NC passed the test of disintegration in compost, evidencing no toxicity on germination of cress seeds. The process of production of NC fibrils, was mostly affected by the high consume of water, and use of chemicals thus plans for recovery and re-use of the water based buffer will improve the sustainability of the process. The bio-nanocomposites based on PLA and NC have a positive environmental effect due to being based on natural resources and having compost ability as possible end of life scenario.