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US 5,470,944 AGranted
Production of high molecular weight polylactic acid
AssigneeArch Development Corporation
InventorPatrick V. Bonsignore
Life of this patent
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Abstract
A degradable high molecular weight poly(lactic acid). A poly(lactic acid) has a terminal end group of one of carboxyl or hydroxyl groups with low molecular weight poly(lactic acid) units coupled with linking agents of di-isocyanates, bis-epoxides, bis-oxazolines and bis-ortho esters. The resulting high molecular weight poly(lactic acid) can be used for applications taking advantage of the improved physical properties.
Claims13
A poly(lactic acid) having an average number molecular weight of about 25,000-100,000, comprising:
- poly(lactic acid) polymeric units having terminal end groups selected from the group consisting of one of carboxyl and hydroxyl groups, said polymeric units coupled one to another by coupling agents selected from the group consisting of bis-epoxides, bis-oxazolines and bis-orthoesters.
A co-polymer having an average number molecular weight of about 20,000-100,000, comprising:
- monomers selected from the group consisting of lactic acid, glycolic acid, and mixtures thereof;
- and
- monomers selected from the group consisting of propylene glycol, ethylene glycol, and bis-hydroxyethyl sulfone, said co-polymer coupled one to another by coupling agents selected from the group consisting of bis-epoxides, bis-oxazolines, and bis-orthoesters.
Dependencies are inferred from the claim text.