Cellulose nanocrystals make plastic 3,000 times stronger
Researchers at the SUNY College of Environmental
Science and Forestry are developing ways to use cellulose from wood to
strengthen plastics, providing a lightweight component that has the added
advantage of being biodegradable.
Researchers at the SUNY College of Environmental Science and Forestry are developing ways to use cellulose from wood to strengthen plastics, providing a lightweight component that has the added advantage of being biodegradable.
The key is pulling nanocrystals of cellulose out of natural materials, ranging from trees and willow shrubs to orange pulp and the pomace left behind after apple cider production, and mixing them with plastics.
“By adding an ounce of crystals to a pound of plastic, you can increase the strength of the plastic by a factor of 3,000,” said Dr. William T. Winter, a chemistry professor and director of the Cellulose Research Institute at ESF. “And in the end, in a landfill, it’s just carbon dioxide and water, which can be taken up and made into more biomass.”
The process provides another use for the one billion tons of biomass than can be produced annually in the United State, according to an estimate from the U.S. departments of energy and agriculture. The term “biomass” refers to any biologically derived material.
“All plant materials contain a minimum of 25 percent cellulose,” Winter said. “Wood from trees is a little higher, between 40 percent and 50 percent.”
In addition to being used as strengtheners in plastics, the nanocrystals can be used in ceramics and in biomedical applications such as artificial joints and disposable medical equipment. Using cellulosic nanocrystals to strengthen plastics has advantages over the glass that is often used: Glass is heavier, harder on processing machinery and therefore more expensive to work with, and it stays in the ground for centuries. The cellulose nanocrystals will break down quickly in a landfill.
“Anything which is made in nature can be destroyed in nature,” Winter said. “And these cellulose particles have a lifetime in a landfill of less than 90 days, at which time, they go back into carbon dioxide and water. It can be reabsorbed by other plants that use it to make more cellulose.”
“Just one word: Plastic!”
Posted: Sun - October 22, 2006 at 06:09 AM