In order to solve the increasingly serious problem of marine plastic pollution and protect the marine ecological environment, Chinese scientists have recently developed a polyester composite that can degrade in seawater. It is expected to replace the existing non-degradable general-purpose plastics in many fields.
Wang Gexia, senior engineer of the Institute of Physics and Chemistry of the Chinese Academy of Sciences, said that the water-soluble and degradable materials developed by the team have certain environmental tolerance and can be degraded in seawater within days to hundreds of days after disposal. , eventually decomposed into small molecules that will not pollute the environment.
Wang Gexia said that for a long time people have focused on white pollution on land and its treatment. Until recently, the phenomenon of large amounts of plastic pollution causing the killing of marine organisms has been frequently reported to cause widespread concern.
According to conservative estimates, humans put 4.8 million tons to 12.7 million tons of plastic waste per year to the ocean, accounting for 60% to 80% of total marine solid pollutants. Currently, human activities and ocean currents cause these plastic wastes to be concentrated in the North Pacific. , South Pacific, North Atlantic, South Atlantic and Central Indian Ocean.
The World Economic Forum also warned that the total weight of global marine plastics will exceed the total weight of fish in 2050.
According to experts, almost all types of plastics have been found in the ocean. These plastic particles either float in the sea or sink to the bottom of the sea. They will not decompose for decades or even hundreds of years, causing serious pollution to the entire marine environment. Plastics are discarded directly after use or from land through rivers, winds blow into the ocean, are exposed to light in seawater, weathered by seawater, and by ocean currents and biota, resulting in plastics eventually forming microplastics of less than 5 mm.
Some marine life, such as albatrosses, sea turtles, etc., eating a plastic bag can cause a series of gastrointestinal problems, so that they can no longer eat, and eventually starve to death. The most shocking scientific data shows: 90% of the sea The bird died because of eating a plastic bag.
Wang Gexia pointed out that although the problem of plastic pollution in the ocean is already very serious, there is still no effective response to these plastic pollution. The special marine environment of the ocean makes it impossible to collect and treat such a large amount of scattered garbage as on land. The most fundamental and effective way is to let the material degrade and disappear after it has been discarded into seawater.
According to reports, the Research Group of Degradable Plastics and Engineering Plastics of the Institute of Physics and Chemistry of the Chinese Academy of Sciences is the first unit in China to carry out research on biodegradable plastics. Biodegradable plastics are mostly polymer materials containing ester bonds, and the molecular chains are relatively fragile, so they can be naturally Many microorganisms decompose, digest, and eventually form carbon dioxide and water.
At present, the team's biodegradable plastics production and application technology has been authorized by four Chinese companies, of which three have been successfully put into operation, with a total capacity of 75,000 tons per year, accounting for half of the global total.
After recognizing the seriousness of marine plastic pollution, researchers hope to develop materials that are degradable in seawater. However, they found that biodegradable materials that are rapidly degradable on land are difficult to degrade in seawater, even for long periods of time. Degradation, can not be used to solve the problem of plastic pollution in the ocean.
After repeated experiments, the research team of the Institute of Physical and Chemical Technology combined non-enzymatic hydrolysis processes with water-soluble processes and biodegradation processes to achieve rapid degradation of materials in seawater. Researchers through the design, synthesis, modification and Processing makes its degradation performance can be adjusted according to different application requirements.
In the recent “First Cup” future technology innovation competition held in Shenzhen to enhance China's independent innovation capability and increase the transformation of advanced scientific and technological achievements, this technology ranks among the 30 winning projects.
China has upgraded its ecological environment protection to all previous levels. While solving its own ecological problems, it has also contributed Chinese wisdom to solving global environmental pollution problems.