Depolymerization of polyurethanes under mild conditions
AssigneeEvonik Operations GmbH
InventorsJens Hildebrand, Annegret Terheiden, Natalia Hinrichs-Tontrup, Walter Pfefferle
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Abstract
The present invention relates to an improved process for depolymerization of polyurethanes under mild conditions, wherein polyether polyols and polyamines can be recovered in high yields. The method is practiced by hydrolyzing a polyurethane by contacting with water in the presence of a base containing an alkali metal cation and/or an ammonium cation and having a pKb value at 25° C. of from 1 to 10 and a catalyst selected from the group consisting of quaternary ammonium salts containing an ammonium cation containing 6 to 30 carbon atoms and organic sulfonates containing at least 7 carbon atoms to yield an active hydrogen containing polyether.
Claims19
A method of hydrolyzing a polyurethane, the method comprising:
- contacting said polyurethane with water in the presence of
- a base, the base comprising an alkali metal cation and/or an ammonium cation and having a pKb value at 25° C. of from 1 to 10, and
- a catalyst selected from the group consisting of a quaternary ammonium salt containing an ammonium cation containing 6 to 30 carbon atoms and an organic sulfonate containing at least 7 carbon atoms,
- to yield an active hydrogen containing polyether and an organic polyamine,
- wherein the base is selected from the group consisting of alkali metal phosphate, alkali metal hydrogen phosphate, alkali metal carbonate, alkali metal silicate, alkali metal hydrogen carbonate, alkali metal acetate, alkali metal sulfite, ammonium hydroxide, and a mixture thereof.
Dependencies are inferred from the claim text.