Hamilton, Ontario — Scientists at McMaster University in Hamilton, Ont. have discovered a way to dissolve rubber from old car tires, which they say could eventually remove tires from landfills altogether.
McMaster outlined the method—which is further elaborated upon in the journal Green Chemistry—in a Jan. 13 news release. The process involves breaking down the polymeric oils in the tire by breaking the sulfur-to-sulfur bond and leaving the user with “a large number of ropes” made out of tire rubber, which can then be converted into new products, according to Michael Brook, a professor in the department of chemistry and chemical biology at McMaster.
Brook compares the structure of a tire to a piece of fishnet.
“Essentially, we have found a way to cut all the horizontal lines, so instead of having a net, you now have a large number of ropes, which can be isolated and reprocessed much more easily,” he said.
To drive his environmentally-friendly point home, Brook pointed to a 1990 incident in Hagersville, Ont., in which a massive fire—fueled by a pit of 14 million scrap tires—burned out-of-control for 17 days, spewing toxic smoke into the atmosphere and driving 4,000 residents from their homes.
“Why do people collect in that size? It’s because there’s no real good way to deal with them,” said Brook, adding that recycled tires are typically ground into rubber mulch for playgrounds or asphalt.
While the newly developed method is promising, researchers have cautioned that it has some limitations because it is expensive for industrial applications.
“We’re working on it, but this is the first major step,” said Brook. “This process closes the loop on automotive rubber, allowing old tires to be more easily converted into new products.”