Chemical modification of preformed polybenzimidazole semipermeable membrane
US4634530A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1982 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Jul 6, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2379/06
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for chemically modifying a preformed polybenzimidazole semipermeable membrane is provided. The process comprises the steps of sulfonating the membrane by contacting the membrane at a temperature within the range of 5.degree. C. to 100.degree. C. with a sulfonating agent and heating the membrane in an inert atmosphere at a temperature and for a period of time sufficient to convert the ionic bonds formed in the contacting step to permanent, covalent bonds, thereby providing a covalently bonded sulfonated polybenzimidazole semipermeable membrane. The membrane produced by the process of the present invention exhibits cation selectivity for electrodialysis and electrochemical applications. Other advantages may include increased water flux for reverse osmosis purposes and increased resistance to fouling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.