Sustainable poly(hydroxyurethane)s thermoset adhesives for affixing metals

In the last 5 years, isocyanates-free polyhydroxyurethanes (PHUs), synthesized by step-growth polymerization between biscyclic carbonates and di- or poly-amines, have emerged as a novel class of polyurethanes (PUs). These PHUs find promising applications in flooring, paints, as thermoset materials or (thermal insulation) foams. PHUs can be also exploited advantageously for designing the next generation of high performance polyurethane adhesives. Thanks to the presence of pendant hydroxyl groups favouring the polymer/substrate interactions, the adhesion performances of PHUs may equal or even surpass the ones of conventional PUs. In this contribution, we focused on the design of novel reinforced bio- and CO2-based PHU thermosets adhesives with high shear adhesion strength for metal substrates (aluminium and stainless steel).