Self-healing plastics on the way?

A team led by Jianjun Cheng has used off-the-shelf components to create a polymer that melds back together after being cut in half, without the addition of catalysts or other chemicals. What's more, the researchers say the technique is simple, low cost and scalable. It also works at room temperature. To create the self-healing polymer, the researchers tweaked the structure of a common polymer called polyurea. By making the bonds between the molecules longer, they found that it was easier to pull them apart, but also easier to bond them back together. When samples were cut in half and then left for a day, the team found they had healed back together with the same strength that they had before cutting. In fact, Chang says some of the pieces broke in different places than before, evidence that they had healed completely. The researchers believe the discovery could benefit a range of industries. "This chemistry could modify existing materials to make them more dynamic, healable," Cheng concluded.