US5439985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biodegradable and hydrodegradable diblock copolymers composed of poly(.beta.
Assignee: University of Massachusetts Lowell
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Filing: 1993-07-28
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Granted: 1995-08-08
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Expires: 2013-07-28
Abstract
Abstract A biodegradable and hydrodegradable diblock copolymer includes a naturally-occurring poly( beta -alkanoate) component and a chemically synthesized polyester component formed by ring-opening polymerization. A method of forming the biodegradable and hydrodegradable diblock copolymer having a poly( beta -hydroxyalkanoate) component and a chemically synthesized polyester component includes exposing a naturally-occurring poly( beta -hydroxyalkanoate) to alcoholysis and then to a trialkyl metal to form a dialkyl metal poly( beta -hydroxyalkanoate) macroinitiator. The macroinitiator is then reacted with a lactone or lactide reactant to form the biodegradable and hydrodegradable diblock copolymer.
Inventors
- 👤 Richard A. Gross
- 👤 Stephen P. McCarthy
- 👤 Michael S. Reeve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:49
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
20 words
A biodegradable and hydrodegradable diblock copolymer comprising: a) one naturally-occuring poly(β-alkanoate) segment; and b) one biodegradable polyloactone or polylactide segment.
Claim 2
Dependent Claim
20 words
A biodegradable and hydrodegradable diblock copolymer comprising: a) one naturally-occuring poly(β-alkanoate) segment; and b) one biodegradable polyloactone or polylactide segment.
Claim 3
Dependent Claim
13 words
The diblock copolymer of claim 1 wherein the naturally-occurring poly(β-alkanoate) segment is poly(β-hydroxybutyrate).
Claim 4
Dependent Claim
15 words
The diblock copolymer of claim 2 wherein the naturally-occurring poly(β-alkanoate) has a low molecular weight.
Claim 5
Dependent Claim
12 words
The diblock copolymer of claim 3 wherein the biodegradable segment includes polycaprolactone.
Claim 6
Dependent Claim
12 words
The diblock copolymer of claim 3 wherein the biodegradable segment includes polylactide.
Claim 7
Dependent Claim
17 words
The diblock copolymer of claim 1 wherein the block lengths contain greater than about 10 repeat units.
Claim 8
Independent Claim
95 words
A method for forming a biodegradable and hydrodegradable diblock copolymer of a natural origin poly(β-hydroxyalkanoates) and a biodegradable polyester component, comprising the steps of: a) exposing a naturally-occurring poly(β-hydroxyalkanoate) to alcoholysis, whereby at least one low-molecular-weight poly(β-hydroxyalkanoate) prepolymer, having a hydroxyl end-group and an ester end-group, is formed; b) reacting the hydroxyl end-group of the low-molecular-weight poly(β-hydroxyalkanoate) prepolymer with a trialkyl metal to form a dialkyl metal poly(β-hydroxyalkanoate) macroinitiator; and c) reacting the macroinitiator with lactone or lactide reactant to form a biodegradable diblock copolymer having one naturally-occurring poly(β-hydroxyalkanoate) segment and one biodegradable polyester segment.
Claim 9
Independent Claim
95 words
A method for forming a biodegradable and hydrodegradable diblock copolymer of a natural origin poly(β-hydroxyalkanoates) and a biodegradable polyester component, comprising the steps of: a) exposing a naturally-occurring poly(β-hydroxyalkanoate) to alcoholysis, whereby at least one low-molecular-weight poly(β-hydroxyalkanoate) prepolymer, having a hydroxyl end-group and an ester end-group, is formed; b) reacting the hydroxyl end-group of the low-molecular-weight poly(β-hydroxyalkanoate) prepolymer with a trialkyl metal to form a dialkyl metal poly(β-hydroxyalkanoate) macroinitiator; and c) reacting the macroinitiator with lactone or lactide reactant to form a biodegradable diblock copolymer having one naturally-occurring poly(β-hydroxyalkanoate) segment and one biodegradable polyester segment.
Claim 10
Dependent Claim
19 words
The method of claim 7 wherein the alcoholysis includes methanolysis and whereby the ester end-group is a methylester end-group.
Claim 11
Dependent Claim
11 words
The method of claim 8 wherein the trialkyl metal includes triethylaluminum.
Claim 12
Dependent Claim
21 words
The method of claim 9 wherein the naturally-occurring poly(β-hydroxyalkanoate) includes poly(β-hydroxybutyrate), whereby the dialkyl metal poly(β-hydroxyalkanoate) macroinitiator includes diethyl aluminum poly(β-hydroxybutyrate).
Claim 13
Dependent Claim
28 words
The method of claim 10 wherein the macroinitiator is reacted with ε-caprolactone to form a biodegradable diblock copolymer which includes one naturally-occurring poly(β-hydroxybutyrate) segment and one polycaprolactone segment.
Claim 14
Dependent Claim
30 words
The method of claim 10 wherein the macroinitiator is reacted with a lactide monomer to form a biodegradable diblock copolymer which includes one naturally-occurring poly(β-hydroxybutyrate) segment and one polylactide segment.
Claim 15
Dependent Claim
12 words
The method of claim 12 wherein the lactide is a (L,L)-lactide monomer.
Claim 16
Dependent Claim
12 words
The method of claim 12 wherein the lactide is a (D,L)-lactide monomer.
Claim 17
Dependent Claim
13 words
The method of claim 12 wherein in the lactide is a meso-lactide monomer.
Claim 18
Dependent Claim
12 words
The method of claim 12 wherein the lactide is a (D,D)-lactide monomer.
Claim 19
Dependent Claim
34 words
The method of claim 12 wherein the lactide includes at least on lactide selected from the group consisting essentially of: an (L,L)-lactide monomer; a (D,L)-lactide monomer; a meso-lactide monomer; and a (D,D) lactide monomer.
References Cited (Backward Citations)
US5124371A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-08-07 | 1999-02-06 | 1999-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-07 | 2003-02-06 | 2003-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-07 | 2007-02-06 | 2007-08-08 | $7700.00 | Window Closed / Lapsed |