(DE4422158-A1)      Homogeneous polymer blend contains: (A) at least one sulphonated aromatic polyetherketone; (B) at least one aromatic polysulphone; and (C) 5-30 wt.% of at least one hydrophilic polymer chosen from polyvinylpyrrolidone, polyglycol dialkylether, polyglycol dialkyl ester or poly-[1-(2-oxo-1-pyrrolidinyl) ethylene-co-1-(acetyloxy)ethylene]. The wt. ratio of (A) to (B) is 1-99:99-1. Also claimed is the prepn. of the blend by removing an aprotic organic solvent from a soln. contg. (A)-(C).    USE -   The blends are suitable for the prepn. of moulded articles, films, (a)symmetric membranes, coatings, fibres or iron exchange membranes (claimed), esp. membranes for electrolysis cell, fuel or ultra-filtration.    ADVANTAGE -   The blends have improved mechanical properties (esp. tear strength), stability to acids and bases, and working temp. compared with e.g. sulphonated polyetherketones, the properties remaining unaffected in spite of the hydrophilic component addn.    (JP8020716-A)      Homogeneous polymer blend contains: (A) at least one sulphonated aromatic polyetherketone; (B) at least one aromatic polysulphone; and (C) 5-30 wt.% of at least one hydrophilic polymer chosen from polyvinylpyrrolidone, polyglycol dialkylether, polyglycol dialkyl ester or poly-[1-(2-oxo-1-pyrrolidinyl) ethylene-co-1-(acetyloxy)ethylene]. The wt. ratio of (A) to (B) is 1-99:99-1. Also claimed is the prepn. of the blend by removing an aprotic organic solvent from a soln. contg. (A)-(C).    USE -   The blends are suitable for the prepn. of moulded articles, films, (a)symmetric membranes, coatings, fibres or iron exchange membranes (claimed), esp. membranes for electrolysis cell, fuel or ultra-filtration.    ADVANTAGE -   The blends have improved mechanical properties (esp. tear strength), stability to acids and bases, and working temp. compared with e.g. sulphonated polyetherketones, the properties remaining unaffected in spite of the hydrophilic component addn.    (US5834566-A)      Homogeneous polymer blend contains: (A) at least one sulphonated aromatic polyetherketone; (B) at least one aromatic polysulphone; and (C) 5-30 wt.% of at least one hydrophilic polymer chosen from polyvinylpyrrolidone, polyglycol dialkylether, polyglycol dialkyl ester or poly-[1-(2-oxo-1-pyrrolidinyl) ethylene-co-1-(acetyloxy)ethylene]. The wt. ratio of (A) to (B) is 1-99:99-1. Also claimed is the prepn. of the blend by removing an aprotic organic solvent from a soln. contg. (A)-(C).    USE -   The blends are suitable for the prepn. of moulded articles, films, (a)symmetric membranes, coatings, fibres or iron exchange membranes (claimed), esp. membranes for electrolysis cell, fuel or ultra-filtration.    ADVANTAGE -   The blends have improved mechanical properties (esp. tear strength), stability to acids and bases, and working temp. compared with e.g. sulphonated polyetherketones, the properties remaining unaffected in spite of the hydrophilic component addn.