Cracking The Password Of Components That Change Plastics Back Into New Plastics

All packaging that we regard as disposable may eventually be reborn. Researchers have cracked the code of turning plastics back into components for manufacturing new plastics, which will completely change the status quo of recycling.

Researchers at the University of California, Berkeley have developed a new catalytic process, which can evaporate polyethylene (disposable bags) and polypropylene (hard plastics) in garbage dumps and convert them into propylene and other hydrocarbon gases. These gases can then be used as raw materials to re manufacture the original plastics, thereby realizing a true circular economy.

John Hartwig, Professor of Chemistry, University of California, Berkeley Hartwig) said, "Many things around us are made of these polyolefins. In principle, what we can do now is to split the usually stable carbon carbon bond through the chemical reaction we designed, and bring these objects back to the starting monomer. "

This breakthrough is significant because polyethylene and polypropylene plastics account for almost two-thirds of the global plastic waste. About 80% Eventually, it is incinerated, buried, or discarded into the environment in the form of microplastics, and finally enters our bodies.

Many people have tried to recycle these plastic polymers effectively, but all failed. However, Hartwig's team has now achieved this goal by using cheap solid catalysts, which can operate continuously on a large scale.

The researchers used two different catalysts for the chemical decomposition of polyethylene and polypropylene plastic waste. The first catalyst splits the polymer chain, leaving the active end. The second kind of catalyst completely uncouples these chains by repeatedly exposing the active end to ethylene gas. Finally, propylene and propylene molecules are generated. Another by-product is valuable isobutene gas. All three substances are used in the chemical industry to make different plastics.

For example, propylene is a plastic resin used to make clothes, bottles, furniture and many other products. Propylene is a monomer used in the production of various plastics. Finally, manufacturers use isobutene gas to produce polymers such as butyl rubber and high octane aviation gasoline.

Hartwig said, "We are closer than anyone to making polyethylene and polypropylene have the same recyclability as polyester in water bottles."

Although companies are trying to reduce plastic consumption as part of the recent global green awakening, it is almost impossible to replace this "magic material". A recent United Nations study shows that the growth rate of e-waste is five times that of recycling. In addition, a study by Columbia University found that the current global recycling system has basically collapsed. Berkeley's technology may change the rules of the game.