Increasing the stability of self-healing polymer networks
German researchers from Friedrich Schiller University Jena and Leibniz Institute for Photonic Technology have utilised a reversible thiol-ene click reaction to design novel self-healing polymers.
These materials are based on a new methacrylate monomer featuring a benzylcyanoacetamide derivative, which is copolymerised with butyl methacrylate. Afterwards, the crosslinking is performed by the addition of a dithiol and a tetrathiol, respectively.
Reversible covalent bonds
Self-healing behaviour is obtained by heating the crosslinked polymers to 100 °C (150 °C) for several hours and is monitored by scratch healing experiments utilising an optical microscope. The thermal properties are studied in detail by differential scanning calorimetry as well as thermogravimetric analysis. Moreover, depth-sensing indentation measurements are performed to determine the mechanical properties. The healing process is based on the reversible cleavage/closing of the bonds (i.e., thiol-ene reaction), which could be demonstrated by Raman spectroscopy.
The study is published in: Applied Polymer Science.
