A research group at Purdue University, West Lafayette, Ind., USA, reported this week it is using cellulose’s properties to make more sustainable products like laminated films.

 

 

 

This group, led by Jeff Youngblood (photo), professor in materials engineering, works with nanocellulose fibers to make stronger and more renewable materials than glass. According to Youngman Yoo, a third-year graduate student in Youngblood’s research group, traditional plastics are usually made from petroleum, and making and disposing of them takes up a lot of energy.

"Plastic is very useful; we can’t live without it," Yoo said. "However, we should know it is a main factor of carbon dioxide emission."

To reduce overall carbon use and emission, many scientists and engineers are trying to develop bioplastics. Youngblood’s group, in particular, is developing them from spinning nanocellulose fibers.

"It turns out that a (plant) cell wall has multiple layers, with fibers running in different directions in a matrix," Youngblood said. "Nature figured out how to do this half a billion years before humans. It’s actually optimized as a pressure vessel, which helps its rigidity."

Keeping these properties in mind, Professor Youngblood then decided to use cellulose to make nanocomposites, which are then used to make laminated films and, in one special case, pins for the U.S. Forest Service. "We were trying to drum up support for commercialization in nanocellulose," Youngblood explained.

Nanocellulose can also be given barrier properties to prevent oxygen or water transmission in food packaging and good "wet strength," or better strength when immersed in water. Paper, for example, does not have good "wet strength."

"We can make films that have half the elastic modulus of glass, even though it’s a polymer," Youngblood said. He also added that nanocellulose fibers are similar to glass fibers, except they are stiffer and stronger. These polymer fibers can be spun to make textiles and other products.

"We are trying to replace glass fiber," Youngblood said.

Francisco Montes, another student working with Youngblood, is working on cellulose nanocrystal characterization, which varies depending on how it’s dispersed in water. Nanocrystals can be dispersed in water and can only be seen through a special filter.

"Cellulose nanocrystals show potential advantages when mixed with inorganic particles, offering a sustainable alternative to some industrial processes," Montes said.

Youngblood hopes to someday commercialize these products because of their sustainability and many properties. Fiberglass cannot be recycled but nanocellulose fibers can since they are organic. Shane Peng, a fourth-year graduate student in Youngblood’s group, also agreed.

"Nanocellulose (has an) intriguing combination of mechanical, thermal, and optical properties, and it (has) vast potentials in different applications such as polymer composite, biomedical devices, electronics, membranes, etc." Peng said. "(Our research) is also for a good cause as we are trying to improve the sustainability of commercial polymers while enhancing their properties at the same time by utilizing nanocellulose.