Advantages of degradable polymer materials

2022-06-14
  • Detail

Advantages of degradable polymer materials

in the world, millions of tons of waste plastics are discarded every year, most of which are directly thrown into the sea. Some plastic wastes that are not thrown into the sea form white pollution on land

Many people believe that plastic waste will eventually decompose, but this decomposition may take 50 years, which is unexpected. In this long 50 years, a lot of garbage accumulated on the sea and land, especially plastic garbage floating on the sea, which was mistaken for jellyfish and other food by marine animals, resulting in ecological imbalance. A large number of plastic fishing gear thrown into the ocean every year will entangle marine animals, which is another kind of harm

in order to reduce the harm of plastic waste, people first think of replacing plastic with pollution-free and degradable packaging materials, and replacing white plastic tableware with benign and safe tableware

people first think of returning to nature. Paper is the earliest packaging material. However, papermaking needs to consume a lot of wood, so that the insufficient forests are cut down and reduce the earth's vegetation. In addition, the most troublesome thing is that the modern paper industry is a major polluter. It causes no less pollution to rivers and lakes than plastic waste. Therefore, people of insight today believe that paper packaging and paper tableware should not be vigorously promoted

some chemists focus on making packaging materials and tableware with starch. The advantages of starch are: ① it is non-toxic; ② The raw materials for making starch come from agriculture, with rich sources and low prices; ③ Starch is an easily degradable compound, which can be degraded through the process shown in the figure below. The final product is non-toxic, harmless and highly safe glucose

figure degradation of starch

of course, chemists have not given up taking measures on the plastic itself to reduce environmental pollution. Plastics are made of polymer compounds, which are long-chain molecules composed of repeated groups. Chemists have found some ways to change the structure of polymer compounds and make them easy to degrade

one method is to add photosensitive groups between a certain distance of the molecular chain of polymer compounds. When they are exposed to the sun, the photosensitive groups absorb radiation and break the polymer compounds here. The broken fragments are relatively easy to be biodegraded. The specific method is to add ketone groups to polymers (such as the most common plastics polypropylene, polyethylene, etc.) to form ketone polymers. The photolysis reaction can occur when the sampling rate of sunlight can reach 200 times per second

another method is to introduce some groups into the polymer compound to make it suitable for the taste of some microorganisms. These microorganisms can break the long-chain molecules of the polymer compound into small fragments, and it is easier for the small fragments to be further degraded

this article comes from the Internet. The copyright belongs to the original author. At the same time, it can also allow the designer to give free and diversified play to the design imagination. It is only for everyone to share and learn. If the author believes that infringement is involved, please contact us and delete it immediately after verification

一岁半孩子消化不良总是半夜啼哭
缓解小孩肚子疼呕吐的应急方法
广州掉头发很厉害怎么办吃什么好
北京小孩拉肚子是什么原因

Copyright © 2011 JIN SHI