Gluing and de-gluing "at the push of a button" is particularly popular in industry. The de-adhesive allows repairs to be carried out on the component, and sorted recycling is also made easier. It is important that the adhesive bond remains reliable despite everything under the conditions of use. The loosening of the connection must therefore only take place in a controlled manner and at a specified time.
An adhesive bond can be separated both chemically and physically. Preference is given to physical separation processes, which can be subdivided into thermal and mechanical processes. A thermal separation process is the pyrolysis of the adhesive. Depending on the temperature range, this can also lead to damage to the joining partners. With the mechanical methods, the connection is separated by cutting or breaking open, which can also cause damage to the parts to be joined. A combination of thermal and mechanical separation processes offers the incorporation of blowing agents. The propellant increases its volume enormously above a certain temperature. This reduces the strength of the bonded joint and allows easy separation of the joint partners.
The overarching goal of the project is to research sustainable adhesive formulations and processing methods that enable the reversible bonding and debonding of joining partners that can be triggered by induction. In terms of the tender for the protection of technological resources by the Baden-Württemberg Ministry of Finance and Economics, the work planned in the project represents an important contribution to a safe, stable and affordable supply of raw materials, as it involves efficient joining and cutting processes as well as non-destructive separation and reuse or the enable material recycling of components made from strategically important and economically attractive materials.
Fast adhesive curing by an external stimulus enables fast curing with a long working time. By "formulating" nanoparticles and blowing agents, better properties of the adhesives are to be achieved than by mixing them in.
The essential, innovative aspect of the project consists in the use of biogenic, hyper-branched polypeptides, for the functionalization of which covalently cross-linkable groups, blowing agents and polymer-bound nanoparticles are used as essential building blocks of the adhesive formulations. For the inductive hardening/switching of the adhesives, improved scalability should be achieved in comparison to existing solutions based on high-frequency technology through the use of new inductors at lower frequencies. This approach aims to solve the many problems that have arisen with the introduction of switchable adhesive bonds in adhesive bonding technology.