Membranes and their manufacture
AssigneeVictrex Manufacturing Limited
InventorPhilip J. Brown
Life of this patent
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Abstract
Membranes comprising an aromatic ether ketone polymer (e.g. polyetherketone) in sheet or hollow fibre form are made by preparing at least a 12 wt % solution of the polymer in a solvent which is chemically inert to the polymer (e.g. concentrated sulphuric acid); forming a film of the solution in sheet or hollow form; and contacting the film with a non-solvent (e.g. more dilute sulphuric acid or acetic acid) thereby to precipitate the film.
Claims9
A method of making a membrane of sheet or hollow fibre form, the membrane comprising an aromatic ether ketone polymer comprising O-phenyl-C(O)- units substantially free of —O-phenyl-O— or other electron rich readily sulphonatable units, the method comprising the steps of:
- a) preparing a solution of the polymer in a solvent which is chemically inert to the polymer, the concentration of the polymer in the solution being in the range 15-20%;
- b) forming a film of the solution in sheet or hollow fibre form;
- and
- c) contacting the film with sulphuric acid of concentration in the range 55-72%, thereby precipitating the membrane of said polymer.
Dependencies are inferred from the claim text.