CA1170001A
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Method for preserving porosity in porous materials
Assignee: Massachusetts Institute of Technology
•
Filing: 1981-07-15
•
Granted: 1984-07-03
•
Expires: 2001-07-15
Abstract
Abstract ABSTRACT A dimensionally-stable, non-collapsible highly porous foam based upon an insoluble protein-based polymeric material, is produced by forming a liquid dispersion of an insoluble protein-based polymeric material which does not flow under elevated tempera-tures, quickly freezing the dispersion to form frozen liquid particles, subliming the frozen liquid particles to produce a highly porous foam, and subjecting the highly porous foam to elevated temperature and vacuum conditions sufficient to stabilize the highly porous foam so that its porosity is preserved when it is contacted with a liquid solution of a chemical cross-linking agent. The stabilized highly porous foam is then subjected to a liquid solution of a chemical crosslinking agent so as to produce a dimensionally-stable, non-collapsible highly porous foam material.
Inventors
- 👤 Ioannis V. Yannas
- 👤 John F. Burke
- 👤 Peter J. Stasikelis
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-10-23 07:53
CPC Classifications
—
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
A method of producing a dimensionally-stable, non-collapsible highly porous foam based upon an insol-uble protein-based polymeric material, comprising: a. forming a liquid dispersion of an insoluble protein-based polymeric material which does not flow under elevated temperatures; b. quickly freezing said dispersion to form frozen liquid particles; c. subliming said frozen liquid particles to produce a highly porous foam; d. subjecting said highly porous foam to elevated temperature and vacuum conditions sufficient to stabilize said highly porous foam so that its porosity is pre-served when it is contacted with a liquid solution of a chemical cross-linking agent; and, e. subjecting said stabilized highly porous foam to a liquid solution of a chemical cross-linking agent so as to produce a dimensionally-stable, non-collapsible highly porous foam material.
Claim 2
Independent Claim
124 words
A method of producing a dimensionally-stable, non-collapsible highly porous foam based upon an insol-uble protein-based polymeric material, comprising: a. forming a liquid dispersion of an insoluble protein-based polymeric material which does not flow under elevated temperatures; b. quickly freezing said dispersion to form frozen liquid particles; c. subliming said frozen liquid particles to produce a highly porous foam; d. subjecting said highly porous foam to elevated temperature and vacuum conditions sufficient to stabilize said highly porous foam so that its porosity is pre-served when it is contacted with a liquid solution of a chemical cross-linking agent; and, e. subjecting said stabilized highly porous foam to a liquid solution of a chemical cross-linking agent so as to produce a dimensionally-stable, non-collapsible highly porous foam material.
Claim 3
Dependent Claim
15 words
2, A method according to claim 1, wherein said liquid dispersion comprises an aqueous dispersion.
Claim 4
Dependent Claim
15 words
A method according to claim 2, wherein said insolubleprotein-based polymericmaterial comprises cross-linked collagen-mucopolysaccharide composite material.
Claim 5
Dependent Claim
15 words
A method according to claim 2, wherein said insoluble protein-based polymeric material comprises ground leather.
Claim 6
Dependent Claim
18 words
A method according to claim 4, wherein said highly porous foam has a porosity greater than about 95%.
Claim 7
Dependent Claim
16 words
A dimensionally-stable, non-collapsible highly porous foam material produced by 2 method as defined in claim 1.
Claim 8
Dependent Claim
15 words
A highly porous foam according to claim 6 having a porosity greater than about 95%.
Claim 9
Dependent Claim
92 words
In the production of a multi-layer membrane having a first layer formed from an insoluble protein-based polymeric material which does not flow under elevated temperatures and a second layer comprising a moisture transmission control layer, the improvement wherein said first layer comprises a highly porous foam material having a porosity greater than about 95% which has been subjected to elevated temperature and vacuum in order to preserve its porosity and subse-quently contacted with an aqueous solution of a chemical crosslinking agent to cause said highly porous foam to become dimensionally-stable and non-collapsible.
Claim 10
Dependent Claim
92 words
In the production of a multi-layer membrane having a first layer formed from an insoluble protein-based polymeric material which does not flow under elevated temperatures and a second layer comprising a moisture transmission control layer, the improvement wherein said first layer comprises a highly porous foam material having a porosity greater than about 95% which has been subjected to elevated temperature and vacuum in order to preserve its porosity and subse-quently contacted with an aqueous solution of a chemical crosslinking agent to cause said highly porous foam to become dimensionally-stable and non-collapsible.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.