Patent DE-10308462-A1 (DE)
Title: Sulfinate group containing oligomers and polymers useful as membranes for membrane processes, e.g. for proton exchange membrane fuel cells, membrane electrolysis and for production of molded bodies
Inventor: KERRES JOCHEN
IPC: C08G65/48
Filed: 2003-02-21
Abstract: Modified polymers, their blends, membranes, or shaped bodies, each having sulfinate groups SO2M (M = metal, ammonium- imidazolium-, pyrazolium-, or pyridinium ion) undergo sulfinate group Z-alkylation reactions, where ALK can be an alkylation agent or a mixture of these, which under S-alkylation, by substitution or addition (at olefins with electron attracting groups) react with the sulfinate groups are new.  Modified polymers, their blends, membranes, or shaped bodies, each having at least sulfinate group SO2M containing polymer blends, polymer membranes, or shaped polymer bodies which under S-alkylation, by substitution or addition (at olefins with electron attracting groups) react with the sulfinate groups (I); and the alkylating agent can have 1, 2 or more than 2 alkylation groups. M = 1, 2, or 3-valent metal cation, or ammonium ion NR4+; R = H and/or imidazolium-, pyrazolium-, pyridinium ion) undergo sulfinate group Z-alkylation reactions; ALK = alkylation agent or a mixture of these. Independent claims are included for a method of preparing the modified polymers in which the sulfinate group bearing polymer, optionally together with other polymers is reacted with alkylating agent (AA) in a reaction flask, optionally under a shielding gas and optionally dissolved or suspended in a solvent suitable for the organic AA or a mixture of these, and optionally with addition of easily or difficultly soluble Ca compounds to the reaction mixture at 0-200 degrees C, optionally under a shielding gas, with stirring to the end of the reaction.  The reaction mixture is then worked up:  (a) water insoluble product: (1) optional addition of a 2- to 10-fold excess of water, aqueous Ca salt solution, e.g. Ca chloride or gluconate solution and/or aqueous hydroxide solution (1-30 % NaOH, KOH, LiOH, Ca(OH)2, 1-30% ammonia solution or amine solution) relative to a molar amount of AA, to the reaction to avoid excess of AA, and optionally precipitation of fluoride ions released by the reaction as CaF2; (2) precipitation or suspension of the reaction mixture in a 2 to 20-fold excess (relative to the volume of reaction mixture or the modified polymer) of an alcohol (methanol, ethanol, I-propanol, n-propanol), water, or an aqueous mineral salt solution (NaCl, NaHCO3, Na2SO4, CaCl2, etc.) or other precipitation agents (acetone, methylethyl ketone), and filtration; (3)  washing of the precipitate to ion-free water; (4)  drying at increased temperature and optionally decreased pressure;  (5) optional redissolution of the modified polymer and working up as under (2); (b) water soluble product: (1) mixing of the reaction mixture with a to 2 to 20-fold excess of water, Ca salt solution etc. as above; (2) mixing of the reaction mixture with a 5- to 20-fold excess of water and dialysis for removal of all low molecular material;  (3)  filtering off water insoluble components of dialysis; (4) drying at increased temperature and optionally decreased pressure; and (5) forming of the modified polymer obtained to membranes for use in membrane processes or in membrane fuel cells, or membrane electrolytes.