1. Photodegradable plastics
Add photosensitizer into the plastic to gradually decompose the plastic under sunlight. It belongs to the earlier generation of degradation plastics, and its disadvantage is that the degradation time is difficult to predict due to sunlight and climate changes, so the degradation time cannot be controlled.
2. Biodegradable plastics
Under the action of microorganisms, plastics can be completely decomposed into low molecular compounds. It is characterized by convenient storage and transportation, as long as it is kept dry without avoiding light, and has a wide range of applications. It can not only be used for agricultural mulching films and packaging bags, but also widely used in the field of medicine. With the development of modern biotechnology, biodegradable plastics have received more and more attention and have become a new generation of hot spots in research and development.
3. Light/biodegradable plastics
A kind of plastic combining photodegradation and microorganism, which has the characteristics of light and microorganism degradation plastic at the same time.
4. Water degradation plastic
Water-absorbing substances are added to plastics, which can be dissolved after being discarded in water. They are mainly used in medical and sanitary appliances (such as medical gloves) for easy destruction and disinfection.
Ⅲ. Tests:
Show that most degradable plastics begin to become thinner, weightlessness, strength decline and gradually split into fragments after being exposed in general environment for 3 months. If these fragments are buried in garbage or soil, the degradation effect is not obvious.anitary appliances (such as medical gloves) for easy destruction and disinfection.
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What problems will "degradable plastics" bring
Despite the problem of materials themselves, there is no universal industrial composting industry in China at present, and the garbage classification and recycling system is not working well.
Promoting the use of "degradable plastics" may bring new "white pollution". However, the publicity of "degradable plastic" will easily make the public think that it is a kind of material that "can disappear without treatment" and cause misleading.
Returning to the most fundamental problem, the plastic pollution currently facing China and the world is the cost of excessive consumption and irresponsible consumption. Even if "degradable plastics" can be recycled into industrial composts to solve the degradation problem, the consumption of "degradable plastics" is ultimately the consumption of environmental resources. From this perspective, we need to consider how to reduce the source of excessive consumption.
However, we cannot deny that degradable plastics may be a development trend in the future. Deng Xiaogang, director of the ecological environment department of Hainan province, said,
"At present, there is no national standard for total biodegradation products, and there are no relevant standards in other provinces. Therefore, Hainan needs to innovate and make the first real local standard for total biodegradation." This still has its meaning.
Next, it is hoped that this measure of Hainan will push the development and perfection of degradable plastics technology, break the constraints of technology, standard, production, processing process and other aspects for the promotion of degradable plastics in the future, and make it a truly practical and perfect solution in the treatment of "white pollution.
