New catalyst boosts production of biodegradable plastics

Plastic is one of the greatest inventions of mankind in the 20th century, but ordinary plastics are difficult to degrade under natural conditions, and the resulting environmental costs are high. Stanford University and International Business Machines Corporation have developed a new method of organic catalysis for the low-cost and efficient production of biodegradable plastics. The relevant research results have been published in the new issue of the British journal Nature Chemistry.

Unlike conventional plastics that are derived from petroleum, biodegradable plastics are less harmful to the environment. The production of this kind of plastic requires the use of catalysts to increase the conversion rate of chemical reactions. However, the existing catalysts have a metal base, which is difficult to degrade in the natural environment, and it is also difficult or expensive to remove from the final product.

The researchers said that the new catalyst they developed uses common organic compounds as raw materials, namely thiourea and a metal alkoxide. The preparation process is relatively simple and easy to use, and its properties can be adjusted according to the needs of the product. It is suitable for Production of degradable polyester and polycarbonate. While accelerating the chemical reaction, the catalyst is selective in its catalysis, that is, it does not change the shape and properties of the resulting plastic.

"Many catalysts either accelerate or selectively catalyze, and these (new) catalysts do both," said Robert Weymouth, a professor of chemistry at Stanford University.

The new catalyst, aimed at reducing economic costs and environmental hazards, could be used to produce polyester and polycarbonate materials, including stackable and degradable polylactic acid. Polylactic acid is a new type of biodegradable material that can be used in the production of everyday items such as disposable tableware and food packaging, as well as in medical applications such as absorbable sutures, internal implants and fixation brackets.