| abstract |
1367238 Dialysis; ultra filtration RHONEPOULENC SA 30 June 1972 [2 July 1971] 30833/72 Heading B1X [Also in Division C3] Films and membranes useful for fractionating protein solutions and in applications such as artificial kidneys and lungs are formed from complex polyelectrolytes which comprise an ionically crosslinked, polymer which is soluble in a liquid organic medium and which corresponds to the general formula: in which the symbol N<SP>+</SP> represents a quaternary nitrogen-containing group; the symbol represents a first macromolecular chain to which the indicated -SO 3 <SP>-</SP> groups are linked via a divalent radical or a direct bond, the symbol represents a second macromolecular chain, the symbol indicates that the N<SP>+</SP> groups shown are linked to said second macromolecular chain via at least one divalent radical or direct bond, and said macromolecular chains, considered together, do not contain oppositely charged groups which are capable of forming inter chain covalent bonds; the ratio n/m is from 0.1 to 10; and the nature of the units forming the macromolecular chains and the values of n and m are such that the polymer of the formula: in which M represents a hydrogen ion or an alkali metal or alkaline earth metal ion and x is 1 or 2, and the polymer of the formula: in which A represents a hydroxyl radical or the anion of an inorganic or organic acid of formula AHy, y being 1, 2 or 3, are both insoluble in water but soluble in a common liquid organic medium. The films and membranes can be planar, tubular or spiral and may have isotropic (dense structure of uniform porosity) or anisotropic (having a porosity gradient from one face to the other) structure. In Examples the membranes are used to fractionate (e.g. by ultra filtration, inverse osmosis or dialysis) bovine albumen, ovalbumin, lysozyme and cytochrome C. In the Examples the polyelectrolytes are derived from (a) acrylonitrile-sodium methallyl sulphonate copolymer or sulphonated polyaryl ether/sulphone and (b) acrylonitrile/3-vinyl-6-methyl pyridine copolymer quaternised by methyl sulphate, a phenoxy resin quaternised by treatment with epichlorohydrin and then with trimethylamine, or a polyester-quaternised polyurethane. |