Biodegradable additives are additives that enhance the biodegradation of polymers by allowing microorganisms to utilize the carbon within the polymer chain as a source of energy. Biodegradable additives attract microorganisms to the polymer through quorum sensing after biofilm creation on the plastic product. Additives are generally in masterbatch formation that use carrier resins such as polyethylene (PE), polypropylene (PP), polystyrene (PS) or polyethylene terephthalate (PET).
Most common synthetic plastics are not biodegradable, and both chemical and physical properties of plastics play important roles in the process of plastic degradation. The addition of biodegradable additives can influence the mechanism of plastic degradation by changing the chemical and physical properties of plastics to increase the rate of degradation.[1] Biodegradable additives can convert the plastic degradation process to one of biodegradation. Instead of being degraded simply by environmental factors, such as sunlight (photo-oxidation) or heat (thermal degradation), biodegradable additives allow polymers to be degraded by microorganisms and bacteria through direct or indirect attack.
While some plastic additives merely affect the surface of plastics (ex. colorants), effective biodegradable additives must change the interior of the plastics and their chemical properties, as well.[2] Good biodegradable additives expedite the rate of degradation by reducing the strength of certain properties of the polymers and increasing their attractiveness to microorganisms.