OSU chemist seeks cleaner, greener plastics
Thursday, September 27, 2007
OSU chemistry associate professor Jeff White (right) is shown holding a component
from a solid-state nuclear magnetic resonance spectrometer, a device that supports
the resonance techniques his research team has used to challenge conventional thinking
about polymers. Funded by the National Science Foundation and assisted by researchers
such as post-doctoral student Marcin Wachowicz, White is working to simplify the chemical
combinations used in many plastic consumer products. Ultimately, his research may
reduce the environmental impact of manufacturing plastics while simultaneously making
them easier and cheaper to recycle.
(STILLWATER, OKLA. – Sept. 24, 2007) -- Science is filled with complex, seemingly unsolvable problems, but Oklahoma State University chemistry associate professor Jeff White has found that sometimes the simplest questions reveal the most intricate answers.
Armed with the question, “Why don’t some apparently identical polymers mix together at the molecular level?” White received his first National Science Foundation grant in 2001. In September, he submitted a proposal to the NSF for a third renewal.
“I teach students that identical substances will dissolve into each other to form an intimate mixture, and that different substances do not dissolve, like oil and water,” White said. “But when you look at some common polymers used worldwide, called polyolefins, this is not the case.”
Consumers use polymers every day that range from a plastic shampoo bottle to the car dashboard. In order for a polymer to become a consumer product, it is blended with other polymers, but desired weight, strength, flexibility and other properties are achieved by adding components that are not stable in the mixture and that themselves are not polymers.
According to White, eliminating the added substances will make plastics more environmentally friendly and easier to recycle. Successfully combining polymers intimately to form a new material without using unstable, non-polymeric additives, though, is not so much a question of how to mix different ingredients together, as in a cooking recipe, but rather how to make the actual ingredients.
White hopes for a third renewal of NSF funding so his research team can find molecular arrangements that allow the most economically important class of polymers to fit together consistently without additives.
“We want to know, how do we change the structure to make a new mixture that is really a brand new material?” White said.
Previous research about polymers cited enthalpy, or the attraction of one molecule to another, different molecule, as the reason some polymers mix. White and his team proved through a unique method, called Solid-State Nuclear Magnetic Resonance, that previously published research was incorrect for many polymer blends.
White said the reason some polymers mix is due to entropy, or the idea that a polymer molecule wants to maximize a variety of energies.
“Some external reviewers have stated that we rewrote the textbooks on macromolecules in our first phase of research,” White said. “We devised real experiments that showed how entropy controlled mixing in very large molecules.”
White’s project has been the subject of 14 scientific journal articles and book chapters since the NSF began funding it in 2001, including in the Journal of the American Chemical Society.
While supporting sustainable manufacturing processes for greener consumer products, eliminating additives will make more plastics safe for medical and biological uses.
“The additives mixed with polymers to make the right combination of weight, strength and flexibility often prevent materials from being used in medical applications, since those additives can leak out of the material,” White said. “Our team hopes to receive continued NSF funding so that we can focus on what it will take to make longer lasting, reclaimable and economically viable polymer materials.”
To learn more about the OSU Chemistry department, visit http://chemistry.okstate.edu.