Is the new paint up to scratch?
Scratch-free cars are a step closer thanks to a new paint that heals itself in sunlight. Scientists have developed the polyurethane coating which contains chitosan, a substance found in the shells of crabs and shrimp.
'We developed a polymeric material that is able to repair itself by exposure to the sun,' said Marek Urban of the University of Southern Mississippi in Hattiesburg, whose study appears in the journal Science.
'In essence, you create a scratch and that scratch will disappear upon exposure to the sun,' Urban said in an interview on the Science website.
The chitosan is incorporated into traditional polymer materials, like those found in coatings on cars to protect paint. When the car is scratched the chemical structure is damaged, but when it is exposed to ultraviolet light chemical chains are formed.
These begin bonding with other materials in the substance and the scratch is eventually smoothed out – sometimes in less than an hour. The polymer can only repair itself in the same spot once and cannot work on repeated scratches in the same place.
Howell Edwards, who heads the chemical and forensic sciences division of the University of Bradford, said the findings were interesting.
‘Clearly, there are future applications of this work in the repair of automotive components, which extensively use polyurethane polymers, that have suffered minor damage,’ Edwards said in a statement.