Biodegradable plastic refers to the degradation caused by the action of microorganisms in nature under natural conditions such as soil and/or sandy soil, and/or specific conditions such as composting conditions, anaerobic digestion conditions, or aqueous culture fluid, and is completely degraded by the action of microorganisms in nature. Degraded into carbon dioxide (CO2) or/and methane (CH4), water (H2O) and mineralized inorganic salts of the elements contained therein, and new biomass (such as microbial dead bodies, etc.).

According to the raw material source of biodegradable plastics, it can be divided into two types: bio-based biodegradable plastics and petrochemical-based biodegradable plastics.

Bio-based biodegradable plastics can be divided into four categories: one is plastics directly processed from natural materials. Currently, biodegradable plastics produced by natural polymers on the market mainly include thermoplastic starch, biocellulose, polysaccharides and polysaccharides. Polyamino acids and their blended, modified and chemically modified products; the second category is polymers obtained by microbial fermentation and chemical synthesis, such as polylactic acid (PLA), etc.; the third category is polymers directly synthesized by microorganisms, such as Polyhydroxyalkanoate (PHA), etc.; the four categories are biodegradable plastics obtained by blending these materials or blending these materials with other chemically synthesized biodegradable plastics.

Petrochemical-based biodegradable plastics refer to plastics obtained by polymerizing petrochemical monomers by chemical synthesis, such as polybutylene terephthalate (PBAT), polybutylene succinate (PBS) ), carbon dioxide copolymer (PPC), polyglycolic acid (PGA), etc.