Biodegradation is a series of complex processes. First, polymer materials are broken into smaller sizes and shapes (disintegration and biological fragmentation) in the external environment. Then there is depolymerization, that is, polymer macromolecules are decomposed into oligomers, dimers and monomers with lower molecular weight. Depolymerization products are used by microorganisms as carbon sources to produce energy, biomass and various primary and secondary metabolites. Finally, there is the mineralization stage, in which these metabolites are completely oxidized and converted into carbon dioxide, nitrogen, methane, water and different salts.

Polylactic acid biodegradable materials have the following characteristics:

1. They can be treated together with garbage, and can also be made into compost to return to nature;

2. Due to degradation, its volume is reduced and the service life of the landfill site is prolonged;

3. There is no problem that ordinary plastics need to be incinerated, which can inhibit the emission of dioxin and other harmful gases;

4. It can reduce the harm to wild animals and plants caused by random discarding;

5. It is convenient for storage and transportation, as long as it is kept dry and does not need to be protected from light;

6. It can be widely used not only in agriculture and packaging industry, but also in medical industry