Researchers at Washington State University (WSU) have developed an environmentally friendly, plant-based material that for the first time works better than Styrofoam for insulation.

The foam is mostly made from nanocrystals of cellulose, the most abundant plant material on Earth. The researchers also developed an environmentally friendly and simple manufacturing process for the foam, using water rather than other, more harmful solvents.

The work, led by Amir Ameli, assistant professor in the School of Mechanical and Materials Engineering, and Xiao Zhang, associate professor in the Gene and Linda School of Chemical Engineering and Bioengineering, is reported in a paper in Carbohydrate Polymers.

Researchers have been working to develop an environmentally friendly replacement for polystyrene foam, or Styrofoam, which is used in everything from coffee cups to materials for the building and construction, transportation, and packaging industries. This effort is driven by the fact that Styrofoam is made from toxic ingredients, depends on petroleum, doesn't degrade naturally and creates pollution when it burns.

While other researchers have created other cellulose-based foams, these plant-based versions haven't performed as well as Styrofoam. They are not as strong, don't insulate as well, and degrade at high temperatures and in humidity.

In their work, the WSU team created a material that comprises around 75% cellulose nanocrystals from wood pulp. To produce these cellulose nanocrystals, the researchers use acid hydrolysis, in which acid is used to cleave chemical bonds. They then added polyvinyl alcohol, another polymer that bonds with the nanocellulose crystals and makes the resultant foams more elastic. In addition, the foams possess a uniform cellular structure that make them a good insulator.

The researchers report that, for the first time, this plant-based foam surpassed the insulation capabilities of Styrofoam. It is also very lightweight and can support up to 200 times its weight without changing shape. It degrades well, and doesn't produce polluting ash when burnt.

"We have used an easy method to make high-performance, composite foams based on nanocrystalline cellulose with an excellent combination of thermal insulation capability and mechanical properties," Ameli said. "Our results demonstrate the potential of renewable materials, such as nanocellulose, for high-performance thermal insulation materials that can contribute to energy savings, less usage of petroleum-based materials and reduction of adverse environmental impacts."

"This is a fundamental demonstration of the potential of nanocrystalline cellulose as an important industrial material," Zhang said. "This promising material has many desirable properties, and to be able to transfer these properties to a bulk scale for the first time through this engineered approach is very exciting."

The researchers are now developing formulations for stronger and more durable materials for practical applications. They are interested in incorporating low-cost feedstocks to make a commercially viable product and are considering how to move from the laboratory to a real-world manufacturing scale.

This story is adapted from material from Washington State University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.