ABSTRACT
Researchers at I.B.M. and Stanford University said they had discovered a new way to make plastics that can be continuously recycled or developed for novel uses in health care and microelectronics.
FULL TEXT
Researchers at I.B.M. and Stanford University in California have said they have discovered a new way to make plastics that can be continuously recycled or developed for novel uses in health care and microelectronics.
In a paper published Tuesday in Macromolecules, a journal of the American Chemical Society, the California researchers describe how they substituted organic catalysts for the metal oxide or metal hydroxide catalysts most often used to make the polymers that form plastics.
Chandrasekhar Narayan, who leads I.B.M.'s science and technology team at its Almaden Research Center in San Jose, California, said the presence of metal catalysts in plastics meant that they could often be recycled only once before ending up in a landfill.
''When you try to take a product and recycle it, the metal in the polymer continues to degrade the polymer so it gets increasingly less strong,'' Mr. Narayan said. ''If you use organic reactants, you can make certain types of new polymers that are quite different and have other properties plastics don't have.''
That could give new life to the 13 billion plastic bottles thrown away each year in the United States.
''Plastic bottles can be converted to higher-value plastics, like body panels for cars,'' Mr. Narayan said.
Organic catalysts could create a new class of biodegradable plastics to replace those that are difficult to recycle, like polyethylene terephthalate, or PET, which is used in a variety of consumer products, including plastic beverage bottles.
These new green plastics could also potentially be used by the pharmaceutical industry as drug delivery devices to treat cancer, Mr. Narayan said. ''The pharma industry has a lot of good drugs on the shelf that they can't use because they are very toxic,'' he said. ''You could encapsulate drugs in a bioplastic polymer and deliver them directly to the cancer site. The polymer degrades locally at the site and releases the cargo.''
I.B.M. and Stanford scientists have proved that organic catalysts work in the laboratory, Mr. Narayan said, and the company has teamed with the King Abdulaziz City for Science and Technology in Saudi Arabia to develop recyclable PET plastics.
Mr. Narayan said that the organic catalysts were ''dirt cheap'' to make and that I.B.M. was in discussions with pharmaceutical companies and other potential partners about developing a pilot project that could be producing plastics within two years.
''It's really a new class of polymers,'' he said. ''I think it's going to revolutionize synthetic chemistry.''
LOAD-DATE: March 10, 2010
