Polyester hydrogenolytic deconstruction via tandem catalysis
AssigneeNorthwestern University
InventorsYosi Kratish, Tobin J. Marks
Life of this patent
Estimating the term…
Abstract
Provided are methods for depolymerizing polyesters, e.g., PET, PBT, and PEN. In embodiments, a method for depolymerizing a polyester comprises combining a polyester comprising a plurality of ester linking groups (R′C(O)OR), a metal triflate catalyst, and a hydrogenation catalyst, under conditions to cleave a C—O bond in an alkoxy group (OR) of an ester linking group of the plurality of ester linking groups.
Claims3
A method for depolymerizing a polyester, the method comprising combining a polyester comprising a plurality of ester linking groups (R′C(O)OR), a metal triflate catalyst, and a hydrogenation catalyst, under conditions to cleave a C—O bond in an alkoxy group (OR) of an ester linking group of the plurality of ester linking groups to depolymerize the polyester to a dicarboxylic acid and an alkane, wherein the carbon of the cleaved C—O bond is a primary carbon, R is a saturated aliphatic group, and R′ is an aromatic group or a heterocyclic group wherein the metal triflate catalyst is Hf(OTf)4;
- the hydrogenation catalyst is Pd/C;
- depolymerization of polyester is carried out at a temperature of 265° C., for a time period of 24 hours, under a pressure of 1 atm H2, and an (ester):(Hf):(Pd) molar ratio of 400:6:1;
- and said method achieves an initial yield of at least 81% of the dicarboxylic acid, and further wherein the polyester is PET, PBT, or a combination thereof.
Dependencies are inferred from the claim text.