NOVELTY - Stepwise alkylation of prim. polymers giving good yields and controllable ratio of amino groups involves a cycle of deprotonation with an organometallic base and reaction with an alkyl halide.    USE - The polymers and their blends are used as membranes or as hollow fibers for pervaporation, perstraction, gas separation, dialysis, ultrafiltration, nanofiltration or reverse osmosis, particularly in membrane fuel cells, polymer electrolyte membrane electrolysis, electrodialysis and diffusion dialysis (all claimed).    ADVANTAGE - The yields are good, the ratio of primary:secondary and secondary:tertiary amino groups can be controlled and the polymer can be simultaneously covalently and ionically crosslinked.    DETAILED DESCRIPTION - Stepwise alkylation of primary polymers in solution or suspension comprises:    (a) deprotonating the primary amino groups using an organometallic base;    (b) reacting the formed carbanion with an alkyl halide to give secondary amino groups;    (c) further deprotonating the secondary amino groups; and    (d) reacting the formed carbanion with an alkyl halide to give tertiary amino groups.    INDEPENDENT CLAIMS are also included for the following:    (A) quaternization of the above amines by reaction with an alkyl halide(s) in solution or suspension;    (B) polymers and membranes containing secondary, tertiary, primary and secondary, secondary and tertiary amine, or secondary and/or tertiary amine and further electrophilic functional groups;    (C) uncrosslinked and covalently crosslinked anion exchange polymers and polymer membranes obtained as above;    (D) the preparation of acid-base blends and blend membranes from the above polymers by dissolving the basic polymer in a dipolar aprotic solvent together with a sulfonic acid (salt), phosphonic acid (salt) or carboxylic acid (salt) containing polymer, evaporating the solvent and treating with dilute mineral acid to regain the acid form of the blend or blend membrane;    (E) the covalent crosslinking of the blends and blend membranes by mixing a tert. polyamine with an acid polymer in a solvent, adding a dihaloalkane optionally mixed with monohaloalkanes and evaporating off the solvent;    (F) the covalent and ionic crosslinking of acid-base polymers and polymer membranes using a polymer containing tert. amino groups and SOY, PO3Y2 or COY groups (Y = H or monovalent metal cation) in solvent comprising adding a dihaloalkane optionally mixed with monohaloalkanes and evaporating off the solvent; and    (G) the obtained covalent and ionic acid-base polymers and polymer membranes.