Abstract:
The invention relates to a method for producing polyarylene ether beads from a polyarylene ether solution, having the steps of i) separating the polyarylene ether solution in a separating device which is vibrated at a frequency ranging from 10 to 1400 Hz, thereby obtaining drops, and ii) transporting the drops into a precipitation bath, thereby forming polyarylene ether beads in the precipitation bath. The precipitation bath (A) contains at least one aprotic solvent (component (1)) and at least one protic solvent (component (2)), (B) has a temperature of 0 °C to T c , the critical temperature T c in [°C] being determined by the numerical equation T c = (77 - c)/0.58, in which c is the concentration of the component (1) in the precipitation bath in [wt.%], and (C) has the component (1) in concentrations of 5 wt.% to c c , the critical concentration c c in [wt.%] being determined by the numerical equation c c = 77 - 0.58 * T, in which T is the temperature in the precipitation bath in [°C], wherein the wt.% in each case is based on the sum of the wt.% of the component (1) and the component (2) in the precipitation bath.
Abstract:
The present invention relates to a process for preparation of polysulphones with Yellowness Index to DIN 6167 smaller than 19 and of polyether sulphones with Yellowness Index to DIN 6167 smaller than 30, characterized in that the polymerization reaction is carried out in basic, aprotic solvents, using a mechanical agitator which passes close to the wall. The present invention also relates to the polyether sulphones and polysulphones obtainable for the first time by this process, and to the use of these polymers for production of mouldings, foils, membranes and foams.