When research chemist Jeannette García found a candy-size lump of white material in a flask she had recently used, she had no idea what she had created. The material stuck firmly to the glass, so she used a hammer to break it free. But when she turned the hammer on the material itself, it refused to crack. “When I realized just how high its strength was, I knew I needed to figure out what I'd made,” García says.
García, a scientist at IBM Research–Almaden, enlisted the help of several colleagues to solve the puzzle. They found that she had stumbled on a new family of thermoset polymers, exceptionally strong plas-tics that are used in products ranging from smartphones to airplane wings. Thermosets account for about one third of the global polymers produced every year, but they are difficult to recycle. García's new material, nicknamed Titan, is the first recyclable, industrial-strength thermoset ever discovered.
Unlike conventional thermosets, which pretty much refuse to be remolded, the new polymer can be reprocessed through a chemical reaction. García and her colleagues reported their discovery in May in Science.
Global demand for durable, recyclable plastics is expected to soon increase. By 2015, for example, both Europe and Japan will require that 95 percent of car parts produced there be recyclable. “This is a perfect example of a material that would work for that,” García says. But she believes that the new thermoset could also eventually extend into a range of applications—anticorrosive and antimicrobial coatings, drug delivery, adhesives, 3-D printing, water purification, among others.
Titan came with a bonus, too. García and her colleagues discovered a second form of the material—a self-healing, gel-like substance they call Hydro—that forms at lower temperatures. “If you cut it in half and then put it back together, it instantly forms bonds,” García says. It could be used as an adhesive, she notes, or as a self-healing paint. Other, related compounds could follow. “It's not just this one new polymer but a new polymer-forming reaction.” García says.
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