Save
Email
Print
ShareOct. 20, 2010 — Amid ongoing concern about plastic waste accumulating in municipal landfills, and reliance on imported oil to make plastics, scientists are reporting development of a new ultra-light biodegradable foam plastic material made from two unlikely ingredients: The protein in milk and ordinary clay.
The new substance could be used in furniture cushions, insulation, packaging, and other products, they report in the ACS' Biomacromolecules, a monthly journal.
David Schiraldi and colleagues explain that 80 percent of the protein in cow milk is a substance called casein, which already finds uses in making adhesives and paper coatings. But casein is not very strong, and water can wash it away. To beef up casein, and boost its resistance to water, the scientists blended in a small amount of clay and a reactive molecule called glyceraldehyde, which links casein's protein molecules together.
The scientists freeze-dried the resulting mixture, removing the water to produce a spongy aerogel, one of a family of substances so light and airy that they have been termed "solid smoke." To make the gossamer foam stronger, they cured it in an oven, then tested its sturdiness. They concluded that it is strong enough for commercial uses, and biodegradable, with almost a third of the material breaking down within 30 days.
Other social bookmarking and sharing tools:
Story Source:
The above story is reprinted from materials provided by American Chemical Society.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- Tassawuth Pojanavaraphan, Rathanawan Magaraphan, Bor-Sen Chiou, David A. Schiraldi. Development of Biodegradable Foamlike Materials Based on Casein and Sodium Montmorillonite Clay. Biomacromolecules, 2010; 11 (10): 2640 DOI: 10.1021/bm100615a
Note: If no author is given, the source is cited instead.
more 
