METHOD OF PRODUCING THERMALLY OXIDISED FIBRE FROM POLYACRYLONIRILE AND ITS CO-POLYMERS Russian patent published in 2008 - IPC D01F9/22 D01F1/02 

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing thermally oxidised fibres from polyacrylonitrile and its co-polymers, which can be used, for instance, as semi-product for their further processing into carbon fibres. Method includes passing polymer solution in organic solvent through spinneret with further stages of fibre stretching, removal solvent from it and thermal oxidation in presence of oxidant with heating. Before passing polymer through spinneret, at least one cyclic alkylenecarbonate is introduced into solution, in amount 0.2-20 wt % from solution weight. Obtained solution is heated, at least during 6 min within temperature range from 80°C to temperature of solvent boiling. Fibre stretching stage can be carried out after removal of solvent from fibre, as well as before removal solvent from fibre and after its removal.

EFFECT: reduction of duration of fibre thermal oxidation stage 8-15 min with preservation of high operational characteristics of produced fibre.

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