At present, there is no unified international standard definition of biodegradable plastic bags in the world, but the definition of biodegradable plastic bags is that under specific environmental conditions, their chemical structure changes significantly, and standard test methods are used. Determination of changes in properties of plastic bags.

There are two degradation methods for biodegradable plastic bags, which can be divided into:

(1) Biophysical degradation method: When microorganisms attack and erode the polymer material, the polymer components are hydrolyzed, ionized or protonated due to the growth of biological cells. While splitting into oligomers, the molecular structure of the polymer remains unchanged, which is the degradation process of the polymer’s biophysical action.

(2) Biochemical degradation method: due to the direct action of microorganisms or enzymes, the polymer is decomposed or oxidatively degraded into small molecules, and finally decomposed into carbon dioxide and water. This degradation method belongs to the biochemical degradation method.