METHOD OF PRODUCING POLYETHERSULPHONE Russian patent published in 2025 - IPC C08G75/23 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing polyethersulphone. Method of producing polyethersulphone involves the following steps: a. mixing 4,4'-dioxydiphenylsulphone (DODPS), potassium carbonate and aprotic solvent to obtain mixture 1; b. obtaining mixture 2 at the boiling point of the aprotic solvent under conditions of distillation of a mixture of solvent and water; c. mixing mixture 2 with 4,4'-dichlorodiphenylsulphone (DCDPS) and an aprotic solvent at the boiling point of the aprotic solvent under conditions of distillation of a mixture of solvent and water to obtain mixture 3; d. holding mixture 3 at the boiling point of the aprotic solvent under conditions of distillation of the mixture of solvent and water with viscosity of mixture 3, which is not more than 25 Pa*s for up to 49%, inclusive, of the total holding time, as well as not less than 26 Pa*s for 50% inclusive of total holding time, to produce a mixture; e. separating polyethersulphone from the mixture to obtain polyethersulphone; f. drying polyethersulphone to obtain polyethersulphone. Weight ratio of polyethersulphone at step c) and d) ranges from 50.5 to 53.5%.

EFFECT: polyethersulphone obtained using this method has a viscosity number in dimethyl acetamide at 40 °C from 58.6 to 71.6 ml/g, as well as weight-average molecular weight from 85,340 to 104,300 g/mol.

17 cl, 1 dwg, 3 ex