US3950282A
Expired / Lapsed
US
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Polyanhydroglucose biodegradable polymers and process of preparation
Assignee: Individual
•
Filing: 1974-12-06
•
Granted: 1976-04-13
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Expires: 1994-12-06
Abstract
Abstract The biodegradable polymer having the formula: W--M--Z wherein M is a polyanhydroglucose block which does not contain any ester substituents and wherein W and Z are organic diisocyanates having the formula: ##EQU1## or ##EQU2## wherein R is an divalent organic radical and wherein X is a terminal group, --M--Z, --M--W or --M. The process of preparing the biodegradable polymer wherein M contains at least one ester substituted hydroxyl group which comprises deesterifying M to obtain M as a polyanhydroglucose block which does not contain any ester substituents.
Inventors
- 👤 Richard D. Gilbert
- 👤 Vivian T. Stannett
- 👤 Soojaa L. Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:43
CPC Classifications
C; C08; C08B; C08B15/00; C08B15/05; C08B15/06; C08B15/005; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/64; C08G18/6484; C08G2230/00; Y; Y10; Y10S; Y10S260/00; Y10S260/43
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
7 words
The biodegradable polymer having the formula: W--M--Z
Claim 2
Dependent Claim
7 words
The biodegradable polymer having the formula: W--M--Z
Claim 3
Dependent Claim
97 words
wherein M is a polyanhydroglucose block which does not contain any ester substituents and wherein W and Z are organic diisocyanates having the formula: ##EQU9## wherein R is an divalent organic radical and wherein X is a terminal group, --M--Z, --M--W or --M, said biodegradable polymer degrading faster than cellulose, said biodegradable polymer being prepared by reacting a polyanhydroglucose triester oligomer containing hydroxyl end groups with diisocyanates or with isocyanate capped non-cellulosic polymers to produce linear block copolymers containing polyanhydroglucose triester blocks, and subsequently de-esterifying said linear block copolymers to yield said biodegradable copolymer containing polyanhydroglucose blocks.
Claim 4
Dependent Claim
97 words
wherein M is a polyanhydroglucose block which does not contain any ester substituents and wherein W and Z are organic diisocyanates having the formula: ##EQU9## wherein R is an divalent organic radical and wherein X is a terminal group, --M--Z, --M--W or --M, said biodegradable polymer degrading faster than cellulose, said biodegradable polymer being prepared by reacting a polyanhydroglucose triester oligomer containing hydroxyl end groups with diisocyanates or with isocyanate capped non-cellulosic polymers to produce linear block copolymers containing polyanhydroglucose triester blocks, and subsequently de-esterifying said linear block copolymers to yield said biodegradable copolymer containing polyanhydroglucose blocks.
Claim 5
Dependent Claim
28 words
The biodegradable polymer of claim 1 wherein M is a cellulose oligomer block, X is --OH, and R is a polyglycol, a polyester, a polyamide or a polyether.
Claim 6
Dependent Claim
83 words
The process of preparing the biodegradable polymer of claim 1 which comprises reacting a cellulose ester oligomer having hydroxyl and groups with a diisocyanate or with a diisocyanate capped non-cellulose polymer or oligomer, the ratio of said diisocyanate to said cellulose ester oligomer being between about 2.5:1 and 1.5:1, whereby copolymers having a cellulose triester oligomer block are produced by a chain-extension type reaction, and de-esterifying the cellulose triester oligomer block to produce a polyanhydroglucose block which does not contain any ester substituents.
Claim 7
Dependent Claim
28 words
The process of claim 3 wherein said de-esterification is achieved under basic conditions and wherein all or substantially all of the hydroxyl groups of M are ester substituted.
Claim 8
Dependent Claim
14 words
The process of claim 4 wherein said de-esterification is achieved under an inert atmosphere.
Claim 9
Dependent Claim
30 words
The process of claim 5 wherein said de-esterification is achieved using a sodium alkoxide in an alkanol, said alkyl groups being the same and having 1 to 6 carbon atoms.
Claim 10
Dependent Claim
11 words
The process of claim 6 wherein a nitrogen atmosphere is used.
Claim 11
Dependent Claim
28 words
The process of claim 7 wherein M is a cellulose oligomer block, X is acetyl substituted and the ester substituents on the hydroxyl groups of M are acetyl.
Claim 12
Dependent Claim
17 words
The process of claim 8 wherein said sodium alkoxide is sodium methoxide and said alkanol is methanol.
Claim 13
Dependent Claim
17 words
The process of claim 8 wherein said sodium alkanol is sodium ethoxide and said alkanol is ethanol.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |