As we all know, plastics bring many conveniences to our lives, work, and travel, but most of these plastics are extracted from petroleum, and the reserves of petroleum are limited. Not only will they be depleted one day, but when petroleum is extracted, fractionated, and cracked into various products, and further processed into the products we use, carbon emissions, inadequate sewage treatment, and other factors bring more harm to our environment, But that’s not all. During and after the use of the product, plastic has been damaging our ecological environment. In recent years, various news media have reported a lot of “white pollution” of plastic, which threatens the living environment of various organisms, including us.
With the increasing awareness of global green environmental protection, a new biodegradable material has emerged – polylactic acid, which is a perfect substitute for plastic in petroleum products and does not contain bisphenol A or plasticizers. So today we will share with you about how polylactic acid is degraded.
Polylactic acid material is an environmentally friendly material that can be completely biodegradable. After degradation, the total amount of CO2 and water produced is balanced, and it does not increase the greenhouse effect of the atmosphere. It does not cause any pollution to the environment and does not produce any toxic substances. If it flows into soil, sewage, rivers, and oceans, it can be fully decomposed into CO2 and water within 3-6 months under the action of microorganisms such as bacteria.
In terms of performance, PLA has good processing and usage performance, and can be processed using traditional processes such as injection molding, extrusion, and spinning. The fibers, films, sheets, and plates made of PLA have similar performance to chemical general-purpose materials such as polypropylene (PP), polyethylene (PE), polyester fibers (PET, PTT, PBT), and can gradually replace petrochemical fibers and petroleum plastics. Its application fields include clothing, packaging, agriculture, home furnishings Automotive components, 3D printing, biomedicine, and more.
Firstly, degradation is a micro level matter and takes a long time, which is also based on the fact that materials can meet our usage needs in normal environments. The clothes we wear and the plastic products we use also undergo degradation at the micro level, but some materials degrade very slowly, even taking hundreds of years. So degradation cannot be observed with our naked eyes, we just need to understand the truth behind it and know that it is constantly progressing.
From the initial chemistry, it has been known that redox reactions are common among several chemical reactions of substances. Natural organisms, including plants, animals, and microorganisms, undergo oxidative reactions in their metabolism, reproduction, aging, disease, and death.
We should understand that the process of organic matter oxidizing and decomposing within biological cells to produce carbon dioxide and water, and releasing a large amount of energy. Biological oxidation and the combustion of organic matter outside the body are essentially the same in chemistry, following the general laws of oxidation-reduction reactions. The amount of oxygen consumed, final products, and energy released are the same, but at different speeds.
Oxidation reaction is one of the main degradation methods, and the molecular structures of different polymers vary. The presence of oxygen can also exacerbate the destructive effects of light, heat, radiation, and mechanical forces on polymers, leading to more complex degradation reactions. There are ester bonds in polylactic acid molecules that are sensitive to both water and heat. Under high temperature, aerobic, and humid environments, the ester bond cleavage undergoes varying degrees of degradation.
The treatment method for ordinary plastics is still incineration and cremation, causing a large amount of greenhouse gases to be discharged into the air, while polylactic acid is buried in the soil for degradation, and the generated carbon dioxide directly enters the soil organic matter or is absorbed by plants, without being discharged into the air and causing a greenhouse effect.
Polylactic acid has excellent biodegradability, and can be completely degraded by microorganisms in the soil within one year after disposal, generating carbon dioxide and water, without polluting the environment. Unilong’s polylactic acid is a product produced by fermentation of starch (such as corn and rice), truly achieving the goal of “originating from nature and returning to nature”!