New processing technology could make it easier to use plant fibers in automotive polymers, making such plastics more eco-friendly and cost effective for manufacturers.

Technology from a team of Purdue University innovators could provide a more business-friendly option for using cellulose nanomaterials in vehicles, food packaging, and other manufactured items.

It provides a new way for manufacturers to use nanocellulose – a green nanomaterial derived from natural sources such as plant matter. Typically, nanocellulose is mixed with solvents or other dispersants to improve the material’s dispersion in polymers.

“These methods can be very expensive for manufacturers, who must add additional processes and machinery to comply with emission standards that may be impacted by solvent use,” says Jeffrey Youngblood, a professor of materials engineering in Purdue’s College of Engineering.

Cellulosic additives for automotive plastics aren’t new. Companies have experimented with several agricultural waste byproducts such as wheat straw, corn fibers, and agave fibers left over from tequila production. At the 2019 Tokyo Motor Show, the Japanese Ministry of the Environment showed off a supercar made entirely from cellulosic fibers called the Nano Cellulose Vehicle (NCV).

The NCV project derived cellulose from wood, but automakers continue to study agricultural waste byproducts as source candidates, hoping to find an inexpensive stock material while reducing landfill use.

The Purdue team’s method involves mixing the nanocellulose in polymer additives, such as plasticizer, and then compounding that mixture into the polymer instead of blending them directly.

This technique could be applicable to a wide variety of polymers, including nylons used in the automotive industry and polylactic acid and ethylene vinyl alcohol copolymer used in food packaging. It enables easy extrusion or injection molding of nanocellulose into useful products with better, more sustainable properties.

“We created a way to use polymer additives as the solvent to disperse nanocellulose during melt processing,” Youngblood says. “This way, you still have increased properties, but without the pieces of the manufacturing process that require additional emissions-lowering components. This makes using nanocellulose, which is biodegradable, more sustainable as well.”

Advantages of the Purdue technique for large-scale polymer production include:

  • Solvent-free compounding of nanocellulose into polymers
  • Homogenous mixture of hydrophilic nanocellulose, hydrophobic polymer

The innovators have worked with the Purdue Research Foundation Office of Technology Commercialization to patent the technology and are looking for additional partners interested in licensing the technology.

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