METHOD OF SELECTING POLYMER COMPOSITION FOR PRODUCING GAS SEPARATION HOLLOW FIBER MEMBRANES Russian patent published in 2024 - IPC G01N31/16 

FIELD: membrane gas separation.

SUBSTANCE: disclosed is a laboratory titrimetric method for determining a coagulation point of a membrane matrix polymer dissolved in a solvent/non-solvent mixture under study, when adding water as a non-solvent of a precipitation bath for a dry-wet method of forming membranes, which is titration of a pre-prepared diluted polymer solution in the analyzed mixture of components with drops of deionised water to the point of turbidity of the solution, i.e. stable observed coagulation of polymer in presence of water, where after titration the coagulation index of the polymer in the considered solvent/non-solvent mixture is calculated as the ratio of the amount of polymer solution taken in units of weight to the amount of water used for titration of the solution to the moment of stable coagulation of the polymer or "cloud point", wherein for the polymer in question and a polymer composition based thereon, used as a molding solution when producing gas-separating hollow fiber membranes, solvent/non-solvent ratio with a coagulation index in range of 150–350 units is selected.

EFFECT: invention provides versatility, speed and accuracy of selecting the solvent/non-solvent ratio for the polymer composition, used as a molding solution when producing gas-separating hollow-fiber membranes.

2 cl, 2 tbl, 2 ex