Tires of the future could come from the farm as much as the factory as researchers have found a way to turn waste tomato peels and eggshells into sustainable rubber.The researchers discovered that food waste can partially replace carbon black, the petroleum-based filler that has been used in manufacturing tires for more than a century.In tests, rubber made with the new fillers exceeds industrial standards for performance, which may ultimately open up new applications for rubber.The method for turning eggshells and tomato peels into viable - and locally sourced--replacements for carbon black was developed by Katrina Cornish and colleagues from The Ohio State University in the US.
"We found that replacing different portions of carbon black with ground eggshells and tomato peels caused synergistic effects - for instance, enabling strong rubber to retain flexibility," Cindy Barrera, a postdoctoral researcher in Cornish's lab, said in a statement. While the findings could make the manufacture of rubber products more sustainable and also keep waste out of landfills.The researchers found in tests that eggshells have porous microstructures that provide larger surface area for contact with the rubber, and give rubber-based materials unusual properties. Tomato peels, on the other hand, are highly stable at high temperatures and can also be used to generate material with good performance.