Monomer recovery process for contaminated polymers
AssigneeE. I. Du Pont de Nemours and Company
InventorFrancis Glenn Gallagher
Life of this patent
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Abstract
An improved process for recovering depolymerization products from polymers such as polyesters, polyamides, and polyesteramides, especially when the starting polymer content is less than about 98%. The depolymerization and vapor phase recovery of monomers and other reaction products are conducted in the presence of a solid support.
Claims20
Process for recovering reaction products from a reaction mass that comprises a starting polymer which is at least one member of the group consisting of polyesters, polyamides, and polyesteramides having about 2% to 70% by weight of non-polymer contaminants, which process comprises:
- (a) depolymerizing the polymer by means of a depolymerization agent to yield volatile reaction products;
- (b) vapor-phase stripping the volatile reaction products, to yield a stripping agent/product distillate;
- wherein said reaction mass in said depolymerizing and stripping steps comprises from about 5% to about 99% by weight of the reaction mass of a solid support, which solid support is solid under the conditions of steps (a) and (b) and forms a suspended bed, either the quantity or both the quantity and the rate of recovery of reaction products being enhanced over that obtained in the absence of said solid support;
- and
- (c) recovering the reaction products from the stripping agent/product distillate while leaving non-volatile residue material with the support material.
Dependencies are inferred from the claim text.