Effect of spinning bath liquids on the properties of acrylic fibers

Abstract

SynopsisFibers of an acrylonitrile copolymer spun from dimethylformamide solution into nonsolvent spinning baths are found to have tensile and contraction properties which correlate with the aggregating power of the bath.Detailed investigation of the dependence of fiber properties on spinning conditions have been made for polyacrylonitrjle (PAN) and acrylonitrile (AN) copolymers by several groups of workers, notably Takahashill Kambara,2 and 0kamura.a The nature and temperature of the coagulating bath for polymer spun from dimethylformamide (DMF) or dimethyl sulfoxide solution have received careful attention. Systematic variation of the coagulating properties of the spin bath have been achieved by using DMF-water mixtures and have shown, for example, that the tensile strength of the drawn fiber increases rapidly when the spin bath contains more than 80% DMF. Increasing the solvent component of the bath delays the onset of coagulation so that the disorientation effects at the jet face arising from the viscoelastic properties of the polymer solution can be overcome. These considerations will, of course, be affected by the extrusion and draw-off rates, jet hole diameter, and the respective diffusion coefficients factors which, as far as possible, need to be kept constant.Takahashi and Watanabe' have also investigated the effect of other nonsolvents, both as the bath liquid and as a replacement for water in the DMF mixtures. Spinnability of the polymer solution can be measured by the ratio winding speed/extrusion speed which passes through a minimum value as the concentration of DMF in the spin bath is increased.Data obtained by Takahashi and Watanabel for an AN + MA copolymer (96 mole-% AN) are given in Table I, where Cmin is the per cent weight concentration of nonsolvent at the point of minimum spinnability. There is a clear correlation with turbidometric titrations. Coagulation values ( 2 ) for PAN4 are also in close agreement. N o similar trend can be detected in their tensile strength results; this may partly he ascribed t80 the voids present in fibers produced in strong coagulating baths.Climie and Whites have shown that aggregation effects occur in PAN 1499

Recent Advances in MXene‐Based Fibers: Fabrication, Performance, and Application

“…Wet spinning is an effective strategy to integrate MXene nanosheets into the overall fiber structure to achieve high MXene load. Wet spinning has a long history in fiber manufacture, particularly for high‐performance polymer fibers such as acrylic, [ 55 ] rayon, [ 56 ] and spandex fibers. [ 57 ] In recent years, wet spinning technology has become a major technology for the efficient, scalable, and continuous production of long fibers.…”