Case study 2
In the synthesis of polyurethane (PU), there are concerns about the toxicity of the reactants isocyanate and phosgene (a precursor of isocyanate). Non-isocyanate polyurethanes (NIPUs) are a more environmentally friendly alternative. Unlike conventional PU production, the isocyanate-free reaction is insensitive to moisture, which simplifies raw component storage and the synthesis process.
Proposed NIPU applications include chemical-resistant coatings, adhesives, imitation leather or foams. NIPU is synthesized by transurethanation or aminolysis of cyclic carbonates (CC), usually carried out in solvents and in large quantities.
Objectives of SIMPLI-DEMO
In SIMPLI-DEMO, NIPUs are obtained by reacting polycyclic carbonate oligomers with a stoichiometric excess of aliphatic and cycloaliphatic amines with primary amino groups.
The synthesis is carried out both by classical polymerization in laboratory reactors as a benchmark and by REX. Whenever possible, efforts will be made to use bio-based materials, either CC prepared from bio-based materials, such as renewable diglycerol carbonate (DGC), or commercially available bio-based diamines.
In addition to the use of microwave, the process times of all of the above reactions involving multiphase and viscous fluids are determined, at least in part, by mixing and mass transfer times. Although there is no specific literature on ultrasound and NIPU synthesis, based on existing polymerization work (including the EU-funded predecessor project SIMPLIFY), it can be assumed that the application of US is also beneficial in terms of reducing process time, enabling milder process conditions, reducing dispersity, and achieving higher and achieving higher microwaves.