For years, the world has relied on oil-based resins to build everything from wind turbines to high-end sports gear. However, even though the materials are strong, they usually end up in landfills because they are nearly impossible to recycle. Researchers are now showing that we can swap out that oil for sawdust and straw.

New research into bio-based epoxy and polyester resins suggests that we don’t have to choose between being green and having high-quality products. These materials are made from “side streams,” basically the leftovers from the forestry and agricultural industries, and they are proving to be just as tough as the traditional components.

Better Strength

Composite panels made from new bio-resins; Photo: Juha Heiskanen / University of Oulu

The most surprising part of this development is how they might work better. In testing, the bio-based polyester showed significantly more muscle than the commercial versions we use today.

Doctoral Researcher Mikko Salonen said, “The biomass-based polyester resin we developed shows up to 76% higher tensile strength than a commercial fossil-based polyester resin.”

Advertisement

These resins are the “glue” that holds together fiberglass for boats and caravans, or the high-performance composites in industrial parts. If the bio-based versions are stronger, it means we can build more durable products using waste materials instead of drilling for more oil.

A Path Toward Easier Recycling

One of the biggest headaches with current composites is that once they are made, they are permanent. Think of old wind turbine blades piled up because they can’t be broken down. These new bio-resins change that because they are chemically recyclable. They can be broken back down into their raw parts and reused, creating a loop rather than a dead end.

“Bio-based resins will not have a significant price difference compared to fossil resins,” said Senior Research Fellow Juha Heiskanen. “Once bio-based platform chemicals are produced, they can be processed using existing chemical industry production lines.”

The team has already filed three patents and is looking for partners to start larger production.