How the HSZG is researching the circular economy of tomorrow. An interview with Prof. Jens Weber.
The recently launched ERDF project "Evaluation of recyclable materials for electrical engineering" is not Prof. Jens Weber's first interdisciplinary project on the topic of silicones in high-voltage insulators. His ERDF-funded project is about improving the almost 100-year-old successful plastic.
In this interview, the Professor of Physical Chemistry at the Faculty of Natural and Environmental Sciences talks about the potential applications of so-called vitrimers, their connections to high-voltage technology and which books he would recommend to people who are not familiar with chemistry.
Professor Weber, so-called vitrimers have caused quite a stir in the world of chemistry. Can you briefly explain what they are and what they have to do with your research?
Yes, with pleasure. While thermoplastics, such as polyethylene (PE) or polyethylene terephthalate (PET), can be melted down and thus be formed into ever new shapes and can therefore, in principle, be easily recycled, this is not possible for elastomers (e.g. silicones) or duromers (e.g. epoxy resins). Once molded, these materials can no longer be reshaped, which makes them very difficult to recycle. "Vitrimers" can be understood as a generic term for a class of plastics that solves precisely this problem through a "new" type of chemistry - it is now possible to reshape cross-linked plastics.
If vitrimers are such all-rounders, why aren't we already using them in products?
The concept is still quite new, having only been introduced by French researchers in around 2011. In the beginning, it was limited to just a few new classes of materials, but now that the principles are largely understood, a large number of new vitrimer systems have been developed in laboratories around the world in recent years, including silicone elastomers. However, the path from the laboratory to application and production is not easy - in addition to up-scaling, which is not always possible as new chemicals are required in larger quantities, the materials must also meet technical requirements - otherwise they will not be placed on the market. This is where we want to take silicone elastomers as an example and test whether and how the new materials meet the high requirements of high-voltage technology.
Your research group is particularly focused on insulators in high-voltage technology, and there is a successful interdisciplinary collaboration within our university with Prof. Stefan Kornhuber from the Faculty of Electrical Engineering and Computer Science. If you succeed in making silicone elastomers based on vitrimers usable as a material in "real" applications, what effects do you hope for?
First of all, it would be very nice if the new chemistry meant that "production waste", for example, did not have to be disposed of, but could be easily reshaped and used after all. Whether and how insulators can be reused after many years of use is not yet foreseeable, but it would be nice. In any case, given the wide range of applications for silicones, we can make a real contribution to the transition to a circular economy.
For many people, chemicals are synonymous with artificial, unnatural and sometimes even dangerous for us and our environment. Do you have an introductory tip for people who would like to start understanding today's developments?
Well, the image of modern chemistry is of course partly self-inflicted, but we should always realize that chemistry is first and foremost just the study of material transformations (in nature too, of course!) and not bad per se. As a book person, I would probably refer you to some wonderful books, e.g. Jens Soentgen's somewhat unorthodox introduction: "Wie man mit dem Feuer philosophiert: Chemistry and Alchemy for the Fearless" or also "The Elements: Discovery and History of Basic Substances" by Philipp Ball. The modern developments are rather marginalized in these books. A look at a portal of the German Chemical Society (GDCh) on the fascination of chemistry may help.
The interview was conducted by Kristin Sprechert.
