Depolymerization of polyurethanes: regeneration of isocyanates via chemical recycling
AssigneeUniversity of Delaware
InventorsMridula NANDI, Robert M. O'DEA, Thomas H. EPPS, LaShanda T.J. KORLEY
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Abstract
The present invention discloses a one-step polyurethane (PU) depolymerization to recover isocyanates and regenerate both thermoplastic and thermoset PUs. The method uses a halide-containing boron compound to depolymerize PUs directly to isocyanates under mild conditions (e.g., <100° C. in toluene). Also, disclosed herein is depolymerization of both model and commercially available PUs and regeneration of PUs using recovered isocyanates, with molecular weight distributions and thermomechanical properties that are equivalent to virgin PUs with yields of up to 50%.
Claims19
A method for depolymerizing a polyurethane to provide a regenerated isocyanate compound in a single step, the method comprising contacting the polyurethane with a depolymerization agent in the presence of a solvent and a Lewis base,
- wherein the depolymerization agent comprises a halide-containing boron compound, and
- wherein the regenerated isocyanate mixture comprises a mixture of a regenerated isocyanate compound and at least one of an adduct of a polyol and the halide-containing boron compound, an adduct of a chain extender and the halide-containing boron compound, a residual amount of the Lewis base, or an acid-base adduct.
Dependencies are inferred from the claim text.