Biodegradable plastics are plastics that can be decomposed by microorganisms into the water, carbon dioxide (or methane), and biomass under specified conditions. Biodegradable plastics may not be bio-based, they can be derived from renewable raw materials, micro-organisms, and petrochemicals. Universal standards and certifications have been developed to define biodegradable plastic from other plastic products.
Biodegradable plastics can be processed into various products using conventional plastics processing technologies. They can be formed into single-use products or packaging materials via extrusion, injection moulding, and blown moulding, etc. Fillers, such as starch, clay, carbon nanotube, cellulose, etc., can be used to reinforce this system with superior mechanical and barrier properties.
Biodegradable plastics usually possess weak gas barrier properties due to the exist of the ester group. They can be formed into multi-layer packaging with other plastics (i.e. LDPE, PET, PP) via co-injection or co-extrusion process. This yields a compostable product with enhanced moisture resistance and multi-functional properties.