KU Leuven disseminated the third project MOOC, about “Smart design of plastics for improved recycling”. You can watch it on youtube.
Plastics are generally classified into thermoplastics and thermosets, according to their response to heating. Thermoplastics become liquid or plasticize upon heating and harden again upon cooling, which can be repeated in multiple cycles. By contrast, thermosets do no plasticize upon heating and will eventually degrade or pyrolyze at high temperatures.
The problematic recycling of end-of-life thermosets could be resolved by the introduction of dynamic or reversible covalent bonds. Such materials are designated as ‘Covalent adaptable networks’ or CANs. Covalent adaptable network materials based on the unique reactivity of 1,2,4-triazoline-3,5-dione (TAD) components were developed by the university of Ghent. TAD-indole based comonomers were incorporated into existing PU thermoset formulations.