Process of making a porous hollow fiber membrane
US5277851A · kind A · utility
Inventors
Key dates
| Filing date | Sep 4, 1992 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Sep 4, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2201/052
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of making a porous polymeric material by heating a mixture of a thermoplastic polymer and a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of 4.0 to 6.0 to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve. The mixture is then cooled to a temperature so that non-equilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant so that the polymer and surfactant form two intermingled separate phases of large interfacial surface area. The surfactant is then removed from the polymer. The porous polymeric material produced by the above method has a lacey or filamentous structure consisting of a plurality of polymer strands connected together at spaced apart locations along each strand.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.