The Macroporosity of Polyacrylonitrile Fibre

The closed porosity of polyacrylonitrile fibres wet-spun from dimethyl acetamide solutions was investigated in raising the spinning bath temperature from 2 to 20°C. The dependence of the porosity of the fibre on the conditions of plasticization treatment is established. The fibre treated in saturated vapor medium has higher porosity values (narrow transmission factors in chlorobenzene) than the fibre treated with a hot aqueous solution of dimethyl acetamide. The dependence of the fibre porosity on the drying and repeated washing and subsequent drying temperatures is demonstrated. The mobility of the structural elements increases and the porosity of the fibre decreases with an increase in the drying temperature.