Empa researches recyclable epoxy resin
St. Gallen - Researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa) are working on the development of recyclable epoxy resin. Until now, it has not been possible to remelt duromer plastics. However, with the addition of phosphorus additives, recycling should now be an option - both thermally and chemically.
(CONNECT) Researchers from the Advanced Fibers Laboratory at the Swiss Federal Laboratories for Materials Science and Technology (Empa) in St.Gallen are working on the development of a recyclable epoxy resin. This plastic, which belongs to the duromer group and is widely used in aviation, the automotive industry, and wind turbine construction, cannot be melted down due to its long molecular chains. However, the team led by research director Arvindh Sekar has now developed a plastic that can be recycled both thermally and chemically, according to a statement.
To develop a recyclable epoxy resin, the researchers added phosphorus-based additives to the original polymer. Previously, these substances were mixed into the epoxy resin as a powder to give flame-retardant properties. The Empa researchers’ new approach is to add a phosphorus-containing polymer to the epoxy resin before it hardens. The new mixture has the same mechanical properties as the materials used previously, according to the statement. However, the advantage of the new mixture is that after use, it can be ground into powder and pressed into new shapes while heated. This process is also possible with epoxy resins that have been reinforced with carbon or glass fibers. In addition to thermomechanical recycling, the material can reportedly also be chemically cleaned.
“In addition to the fibers, we can also recover over 90 per cent of the epoxy and phosphorus,” Arvindh Sekar is quoted as saying. However, the researcher warns that chemical recycling requires a lot of energy and larger quantities of solvents. “Chemical recycling should always be the last resort,” he added. “Thermomechanical recycling is preferable wherever possible.”
Because the new recycling method eliminates the need for incineration in waste disposal facilities or storage in landfills, it also reduces carbon dioxide emissions, according to the statement. Research has now progressed to the point at which Empa is seeking industrial partners to commercialize the new epoxy resin. ce/ww