Degradable plastics refer to a class of plastics whose products have various properties that can meet the requirements of use, remain unchanged during the storage period, and can be degraded into environmentally sound substances under natural environmental conditions after use.
According to different degradation methods, degradable plastics can be divided into four categories: photodegradable plastics, biodegradable plastics, photo/biodegradable plastics and water-degradable plastics.
Photodegradable plastics refer to plastics that can degrade after being irradiated by light. Once the product is buried in the soil and loses light, the degradation process stops. The production process is simple and the cost is low. The disadvantage is that the degradation process is greatly affected by environmental conditions.
Biodegradable plastic refers to a type of plastic that is degraded by the action of microorganisms in nature such as bacteria, mold (fungi) and algae. Such plastics are convenient for storage and transportation, and have a wide range of applications.
Light/biodegradable plastics are plastics that combine the dual characteristics of light-degradable plastics and biodegradable plastics.
Water-degradable plastic is a plastic that can be dissolved in water because of the addition of water-absorbing substances.
Currently, photodegradation, water degradation, and photo/biodegradable plastics have fewer products due to the limited degradation process and immature technology. The degradation process of biodegradable plastics is less restricted by the environment and can be completely degraded, becoming the mainstream product of degradable plastics. The degradable plastics usually refer to biodegradable plastics.
In addition, according to the classification of raw materials, degradable plastics can also be divided into bio-based degradable plastics and petroleum-based degradable plastics. The former is plastics produced from biomass, mainly including PLA (polylactic acid), PHA (polyhydroxyalkanoate), PGA (polyglutamic acid), etc. The latter is a plastic produced from fossil energy sources, mainly including PBSA (polybutylene adipate), PBAT (polybutylene adipate/terephthalate), PCL (polycaprolactone Ester) etc.