New class of polymers can be endlessly reshaped and recycled
The French scientist Ludwik Leibler is considered a pioneer in polymer physics. With the invention of vitrimers, the professor and director of the Laboratory for Soft Matter and Chemistry at ESPCI ParisTech (Ecole Supérieure de Physique et Chimie Industrielles) has provided the basis for ecological plastic and thus a solution to the steadily growing amount of non-degradable plastic waste.
Vitrimers were born
It only very rarely happens that completely new categories of materials are developed, let alone such that combine seemingly contradictory features. Leibler's new material is as hard as metal, while still being recyclable and repairable. Unlike conventional plastics, it is also endlessly malleable. While trying to develop the new material together with his team he experimented with thermoset plastic. Adding zinc and carboxylic acid as a catalyst turned out to be the breakthrough for the team of researchers. At 150°C an astonishing reaction can be observed: Molecules change their binding partner, while the actual number of bonds among the molecules remains the same. Consequently, the material is malleable without liquefying. Vitrimers were born.
Sturdy alternative to metal and glass
Leibler protected his invention with a patent, not least because of its wide range of potential applications. Explaining the advantages of the new class of plastic, the scientist says: “It is a solid material which is completely insoluble. It can be processed in a very wide range of temperatures and it's 100 per cent recyclable. In contrast to conventional polymers, it also does not suddenly melt.” Vitrimers are a light and sturdy alternative to glass and metal. When heated, they can be welded like metals which allows complex object shapes that are either impossible to obtain by moulding or could only be achieved using very laborious and therefore expensive procedures. Vitrimers could be deployed anywhere where plastic is used, for example in aircraft construction, for bicycle helmets or wind turbine blades.
Organic glue for medical purposes
The vitrimer concept of molecule compounds also opens up opportunities in medical technology: Ludwik Leibler is currently researching a glue made up of silica sand nanoparticles that work similarly to vitrimers. This water-based nanogel can be applied to biological tissue in order to dynamically bind it together and achieve adhesion, thereby sealing wounds or stopping bleeding. “The nanoparticles build variable bonds to the tissue that are strong enough to unite two tissues,” explains Leibler. It only takes two minutes for the mineral nanoparticles to seal open skin wounds or attach medical devices to tissue and organs.
Honoured with the European Inventor Award
For his outstanding achievements, the European Patent Office (EPO) honoured Ludwik Leibler with the European Inventor Award in the “Research” category. The award ceremony at the Palais Brongniart, the historical Paris stock exchange, was attended by some 400 prominent representatives of the fields of politics, science and industry. “Plastics are part and parcel of everyday life,” said EPO President Benoît Battistelli presenting the award. “Thanks to Ludwik Leibler's invention, conventional plastic can now be replaced with recyclable vitrimers, which means that the ecological damage caused by plastic waste can be considerably reduced.”