Some common sense of degradable materials

Biodegradable materials refer to materials that can be degraded by the interaction between natural microorganisms such as bacteria, fungi and algae. This substance can basically be completely decomposed by environmental microorganisms, and then become carbon dioxide and water or methane and water. The degradation products of biodegradable packaging materials can participate in the carbon and nitrogen cycle in nature. Carbon and nitrogen can not only form the basic skeleton of organisms, but also realize the metabolism of organisms through their own biochemical reactions. Therefore, biodegradable plastic packaging material is an environment-friendly material.
Photodegradable plastic packaging materials refer to the materials that will automatically degrade under the action of light. The reaction mechanism is that the plastic will absorb the ultraviolet ray in the sunlight, leading to the reduction of bond energy, the breaking of long polymer chains, and the large molecules become small molecules, and the small molecules continue to undergo oxidation reaction. Free radicals will break chains and small molecular fragments will be completely oxidized by air. Photodegradable plastics can be divided into copolymerization type and addition type.
Copolymer plastic is a kind of plastic formed by co polymerization of carbon monoxide or other olefins and other monomers. The carbonyl chromophores and some weak bonds on the polymer chain are more unstable under light conditions, thus realizing photodegradation. The additive type is to add photosensitizers such as benzophenone into ordinary plastics to make them absorb light of 300nm wavelength, promote intermolecular dehydrogenation, continuously reduce molecular weight, and achieve complete degradation. The necessary condition for photodegradable plastics to be degraded is sufficient light, that is, ultraviolet ray. When the light or ultraviolet ray is insufficient, the material is difficult to degrade and the reaction conditions are harsh.