Rapidly degradable poly (hydroxyacid) compositions
AssigneeE. I. Du Pont de Nemours and Company
InventorHarold E. Bellis
Life of this patent
Estimating the term…
Abstract
The depolymerization of poly(hydroxyacids) in a liquid medium is enhanced by the presence of a quaternary ammonium compound. Poly(hydroxyacid) polymers containing a quaternary ammonium salt are more readily depolymerized.
Claims20
A hydroxyzable composition comprising poly(hydroxyacid) polymer containing, in an amount adequate to depolymerize said polymer, an ammonium salt or a quaternary ammonium compound substantially, fully distributed there through the polymer, said polymer being selected from the group consisting of polylactide, polyglycolide, copolymers of lactide and glycolide, and polymers containing a major proportion of lactide or glycolide units or combinations thereof, polymerized with up to 30% of at least one of the monomers epsilon-caprolactone, delta-valerolactone, 1,5 dioxepen-2-one, 1,4-dioxan-2-one, beta-butyrolactone, beta-propiolactone, 6-methyl-2,5-morpholinedione.
A composition for depolymerization comprising a hydroxyzable poly(hydroxyacid) polymer containing substantially fully distributed therethrough 0.1 to 10% by weight of a quaternary ammonium compound that is reactive with said polymer and a solvent for the depolymerization products of said polymer and said quaternary ammonium compound, said solvent being in contact with said polymer containing the quaternary ammonium compound said poly(hydroxyacid) being selected from the group consisting of polylactide, polyglycolide, copolymers of lactide and glycolide, and polymers containing a major proportion of lactide or glycolide units or combinations thereof, polymerized with up to 30% of at least one of the monomers epsilon-caprolactone, delta-valerolactone, 1,5 dioxepen-2-one, 1,4 dioxan-2-one, beta-butyrolactone, betapropiolactone, 6-methyl-2,5-morpholinedione.
A molding composition comprising
- a moldable solid hydroxyzable said poly(hydroxyacid) selected from the group consisting of polylactide, polyglycolide, copolymers of lactide and glycolide, and polymers containing a major proportion of lactide or glycolide units or combinations thereof, polymerized with up to 30% of at least one of the monomers epsilon-caprolactone, delta-valerolactone, 1,5 dioxepen-2-one, 1,4 dioxan-2-one, beta-butyrolactone, betapropiolactone, 6-methyl-2,5-morpholinedione, and, substantially fully distributed therethrough,
- about 0.1 to about 10% by weight, based on the weight of the poly(hydroxycarboxylic acid), of a quaternary ammonium salt of the formula ##STR4## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are alkyl, unsubstituted or substituted by oxy, amido, or aryl, and X is the anion of a mineral acid or organic acid.
Dependencies are inferred from the claim text.