ETH researchers discover self-repairing corrosion protection by accident


Zurich – Researchers at the Swiss Federal Institute of Technology Zurich (ETH) have developed a plastic that protects metals such as aluminum from decomposition. It can repair itself and shows holes and cracks in the protective layer. It was discovered by accident.

ETH researchers led by Markus Niederberger and Walter Caseri from the Laboratory for Multifunctional Materials have discovered a plastic that can protect metals from corrosion damage. According to a media release, poly(phenylene methylene), or PPM for short, can repair itself and indicates an intact protective layer by glowing.

In addition, the polymer from ETH is more environmentally compatible than conventional corrosion protection, for example from epoxy resins. These must be incinerated or placed in landfills. PPM, on the other hand, is 95 percent recyclable and also repairs itself without the addition of chemical additives. In tests, the researchers were able to reuse the material five times.

Nevertheless, PPM is not entirely harmless to the environment. “Synthetic products always have an impact. But if you choose the right approach, you can greatly limit them,” Marco D’Elia, a former doctoral student at ETH, is quoted as saying.

He was tasked with finding a useful application for PPM after researchers accidentally discovered it ten years ago in Niederberger’s lab while working with an organic solvent. But when they found out that the solvent glows in a polymerized state, “even though it shouldn’t be fluorescent at all according to common ideas,” they developed it further.

In the meantime, the researchers have applied for a patent for their invention, which is still pending. They are currently looking for an industrial partner who would like to further develop PPM and manufacture it on a large scale. They believe the market potential is enormous. According to the data, all countries combined invest $4,000 billion annually in protection against corrosion. ko