New Coating Makes Car Scratches Disappear

Birdman · #1 (**permalink**) 03-16-2009, 06:42 PM

Found this in the news recently......

New Coating Actually Makes Car Scratches Disappear

Friday, March 13, 2009 7:19 AM

CHICAGO -- Scientists have developed a polyurethane coating that heals its own scratches when exposed to sunlight, offering the promise of scratch-free cars and other products, researchers said on Thursday.
"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 self-healing coating uses chitosan, a substance found in the shells of crabs and shrimp. This is incorporated into traditional polymer materials, such as those used in coatings on cars to protect paint.
When a scratch damages the chemical structure, the chitosan responds to ultraviolet light by forming chemical chains that begin bonding with other materials in the substance, eventually smoothing the scratch. The process can take less than an hour.
Urban said the new coating uses readily available materials, offering an advantage over other self-repairing coatings, which he said were "fairly elaborate and economically unfeasible."
The team tested the compound's properties using a razor-blade-thin scratch. "We haven't done any of the tests to show how wide it can be," Urban said in a telephone interview.
He said the polymer can only repair itself in the same spot once, and would not work after repeated scratches.
"Obviously, this is one of the drawbacks," he said, adding that the chances are low of having two scratches in exactly the same spot.
Howell Edwards, who leads the chemical and forensic sciences division of the University of Bradford in Britain, said the findings were novel.
"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.
Urban said the coating could be used in packaging or furniture or anything that requires a high-performance type of coating.
"You can dream up anything you desire," he said.
Urban said his team has patents pending on the material and is considering commercialization.
© Thomson Reuters 2009 All rights reserved

Dad's72Mach · #2 (**permalink**) 03-16-2009, 06:47 PM

Awesome! USM has a topflight Polymer Science Department, I finished undergrad there many years ago.

Carnut · #3 (**permalink**) 03-16-2009, 07:00 PM

Pretty cool, but I don't think I want my paint to smell like fish.

Johnny Dangerously · #4 (**permalink**) 03-16-2009, 07:01 PM

I heard about some self-healing plastic several years ago except they used microscopic capsules that, when broken open by the slice or break, released a liquid polymer that 'healed' the the scratch or cut. It too was limited in how many times a given area is 'healed'.

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gr8snkbite · #5 (**permalink**) 03-16-2009, 07:03 PM

interesting concept....wonder how effective it is with overlaying scratches (i.e scratches that cross each other) since it only repairs once.

Johnny Dangerously · #6 (**permalink**) 03-16-2009, 07:07 PM

Quote:

Originally Posted by gr8snkbite

interesting concept....wonder how effective it is with overlaying scratches (i.e scratches that cross each other) since it only repairs once.

Sounds like you could end up with the occasional dot in some places. Some enterprising chemist will develop some multi-chained, organic compound that mixes well with carnuba wax & acts as a nutrient that replenishes the chitosan.

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