Multistage Chemical Recycling of Polyurethanes and Dicarbamates: A Glycolysis–Hydrolysis Demonstration

The use of polyurethanes and, therefore, the quantity its scrap are increasing. Considering thermoset characteristic most polyurethanes, circular recycling method is by means chemical depolymerization, for which glycolysis finding way into industry. main goal polyurethane to recover polyols used, but only limited attempts were made toward recovering aromatic dicarbamate residues and derivates from used isocyanates. By split-phase method, recovered form a top-layer phase bottom layer contain transreacted carbamates, excess glycol, amines, urea, other side products. hydrolysis carbamates results in amines CO2 as Consequently, can also be hydrolyzed separate process, generating serve feedstock isocyanate production complete material cycle. In this paper, full reviewed experimentally studied. As matter demonstration, combined led an amine yield about 30% model systems. With result, we show high potential further research future optimization reaction conditions catalysis.