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Title: Low density microcellular foams

Abstract

Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the resultant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphologymore » of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Means for subjecting such a solvent to one-dimensional cooling are also provided. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 .mu.m and a volume such that the foams have a length greater than 1 cm are provided.

Inventors:
 [1];  [1];  [2];  [1];  [1];  [3]
  1. Albuquerque, NM
  2. Placitas, NM
  3. Mansfield Center, CT
Issue Date:
Research Org.:
AT&T
OSTI Identifier:
866279
Patent Number(s):
4673695
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01D - SEPARATION
C - CHEMISTRY C08 - ORGANIC MACROMOLECULAR COMPOUNDS C08J - WORKING-UP
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
density; microcellular; foams; microporous; polymer; provided; process; comprises; forming; solution; suitable; solvent; followed; rapid; cooling; form; phase-separated; freeze; phase; substantially; continuous; morphology; prior; subsequent; freezing; determine; resultant; foam; isotropic; anisotropic; produced; tailored; spontaneously; phase-separates; component; freezes; determines; retained; rate; sufficient; components; change; occur; separate; typically; separation; occurs; frozen; two-phase; involves; subjecting; essentially; one-dimensional; means; cc; uniform; cell; size; 10; volume; length; cm; polymer phase; rate sufficient; microcellular foams; solvent phase; rapid cooling; density microcellular; phase separation; comprises forming; polymer foam; suitable solvent; process involves; cell size; microcellular foam; substantially continuous; separation occurs; solvent followed; microporous polymer; cellular foam; phase separate; porous polymer; involves subjecting; /521/210/264/

Citation Formats

Aubert, James H, Clough, Roger L, Curro, John G, Quintana, Carlos A, Russick, Edward M, and Shaw, Montgomery T. Low density microcellular foams. United States: N. p., 1987. Web.
Aubert, James H, Clough, Roger L, Curro, John G, Quintana, Carlos A, Russick, Edward M, & Shaw, Montgomery T. Low density microcellular foams. United States.
Aubert, James H, Clough, Roger L, Curro, John G, Quintana, Carlos A, Russick, Edward M, and Shaw, Montgomery T. Thu . "Low density microcellular foams". United States. https://www.osti.gov/servlets/purl/866279.
@article{osti_866279,
title = {Low density microcellular foams},
author = {Aubert, James H and Clough, Roger L and Curro, John G and Quintana, Carlos A and Russick, Edward M and Shaw, Montgomery T},
abstractNote = {Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the resultant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Means for subjecting such a solvent to one-dimensional cooling are also provided. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 .mu.m and a volume such that the foams have a length greater than 1 cm are provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1987},
month = {Thu Jan 01 00:00:00 EST 1987}
}