| abstract |
1351188 Separation of water from aqueous solutions MONSANTO CO 15 June 1971 [16 June 1970] 27991/71 Heading B1X Water is separated from a liquid or gaseous feed mixture by contact with one side of a water permeable, non-nitrogen containing organic polymer membrane containing at least one anionic group and optional cationic groups. The other side of the membrane is in contact with a vapour phase, preferably flowing having a lower chemical potential than the feed mitxure. The membranes may be discs, sheets, hollow tubes or fibres and may be multilayered. The membranes may be subjected to heat or hydrochloric acid as a pretreatment. The membranes may be made by co-polymerising styrene and acrylic acid with dimethyl formamide and a azobisisobutyronitrile, catalyst. Tertiary butyl catechol is used to stop the reaction. |