Green chemistry could make for easier-to-recycle plastics

US researchers say they might have found a way to more easily recycle plastic bottles or make them safely biodegradable in the environment.

In a paper published in the American Chemical Society journal Macromolecules, scientists from IBM and Stanford University describe how they’re working to develop green organic catalysts that could make it easier to recycle PET (polyethylene terephthalate) plastics such as those used for drink bottles.

“Many people put these in the recycling bin,” said IBM researcher Bob Allen. “It’s difficult to actually use this for new bottles. You cannot use this more than once for a bottle. You have to use it for some other secondary application.”

The right green catalyst, on the other hand, could provide a chemical means of breaking down the long polymer chains in plastics back into the building blocks for new plastic bottles and other products. The process is called “organocatalysis.”

“We can generate new materials from these wonder catalysts we’ve developed that are, for example, biodegradable or biocompatible for use in the body, or in a landfill, they’ll break down into harmless small molecules,” Allen said. “Or we can use the green chemistry catalyst to break down plastics that are in the environment.”

Such a development could help make a serious dent in our plastic waste output, which includes some 13 billion plastic bottles every year. In the US alone, the average person sends around 63 pounds of plastic packaging to the landfill each year.

“We’re exploring new methods of applying technology and our expertise in materials science to creating a sustainable, environmentally sound future,” said Josephine Cheng, IBM fellow and lab director of IBM Research, Almaden. “The development of new families of organic catalysts brings more versatility to green chemistry and opens the door for novel applications, such as making biodegradable plastics, improving the recycling process and drug delivery.”

In medicine, for example, many drugs designed to target cancer cells are often so potent that they attack cancerous and healthy cells alike. The use of organocatalysis could help in the design of custom polymers that could help to better deliver drugs to a specific cell or region.