Rapid depolymerization of polyhydroxy acids
AssigneeE. I. Du Pont de Nemours and Company
InventorsLoren D. Brake, Narayanan S. Subramanian
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Abstract
Recovery of polyhydroxy acids (PHAs) from waste containing high molecular weight polyhydroxy acid polymer by depolymerizing the PHA in water at elevated temperature and pressure.
Claims10
The process of depolymerizing a high molecular weight solid polyhydroxy acid polymer to monomeric hydroxy acid monomer and low molecular weight oligomers comprising mixing said polymer with water at sufficient temperature and pressure for a sufficient time to significantly depolymerize the polymer, said temperature and pressure being insufficient to form undesirable degradation products.
A process for recovering polyhydroxy acid and hydroxy acid value from a polyhydroxy acid polymer-containing source comprising the steps of:
- (a) contacting a polyhydroxy acid polymer-containing material, wherein said polyhydroxy acid polymer-containing material is contaminated with or constitutes trash, with at least one mole of water per mole of hydroxy acid equivalent of said polyhydroxy acid polymer while maintaining the resulting mixture at sufficient temperature and pressure for a sufficient time to depolymerize said polymer and form a liquid phase of enhanced monomer and oligomer hydroxy acid value, said temperature and pressure being insufficient to form undesirable degration products;
- and,
- (b) thereafter isolating and recovering said liquid phase.
Dependencies are inferred from the claim text.