Rheological behavior of aromatic polyamide gel fibres in amide-salt systems

Abstract

For a given polymer-solvent-precipitator system, specific features in the deformational behavior of the gel related both to sharp changes in the quality of the precipitator with a fixed composition and to the components of the spinning medium are observed during precipitation. For certain ratios of solvent (DMAA) and precipitator (water) in the precipitating system, sharp changes are observed in the deformational behavior of the gel fibre, which is confirmed by the uneven changes in the maximum possible spinneret drawing and rheological force (tension in take-up on a disk). These concentration ranges of DMAA (40, 45–55, 55–60, and 60–65% DMAA) are also characteristic of a sharp change in the precipitating power of the coagulation medium, determined with the precipitation number.