Imine als chemische Sollbruchstellen in polymeren Netzwerken für abbaubare 3D-Druck-Materialien

The goal of this work was to develop a photo-reactive resin system that can be selectively cured and degraded using light of different wavelengths. A dual concept was used: a thiol-ene reaction enabled crosslinking at 405 nm, while a photoacid immobilised in the polymer network was intended to be activated at 365 nm to break imine bonds and start the degradation. The main objectives – synthesis and acid-activated cleavage of the imine components, successful incorporation of the photoacid generator, proof of its activation, and wavelength orthogonality between initiator and photoacid – were achieved. However, in the final resin system there was no significant difference in degradation between illuminated and non-illuminated samples, which may indicate insufficient acid activation or limited mobility within the network.
Future work could focus on optimizing the network density, selecting more efficient photoacid generators, and studying diffusion and concentration effects of the activated acid. Despite its limitations, this work provides important insights into acid-activated imine cleavage in resin systems and networks and forms a basis for the development of reversible photopolymers.