A new material design could reduce pollution where the rubber meets the road.
When tires scrape against the road, they drop tiny particles of rubber and plastic polymers, which pollute waterways and contaminate the air (SN: 11/12/18). Every year, tires release an estimated 6 million metric tons of these microplastics into the environment. Stronger polymers that break apart less easily could limit the amount of particles shed annually.
To make such tough materials, Stephen Craig, a chemist at Duke University, and colleagues added molecules called cross-linkers to the polymers. These cross-linkers connected jumbled-up polymer chains to their many neighbors, and they were specifically designed to break apart easily. At the microscopic scale, the polymers act like a tangle of spaghetti strands with the cross-linkers holding them all together and helping them retain their shape, says Craig’s collaborator Shu Wang, a chemist at MIT.
When the team stretched the polymer spaghetti, the individual cross-linkers broke easily, as expected. But the bulk material required more force to rip than they expected.
2023-07-07 08:00:00
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