Abstract
Poly(m-phenylene isophthalamide) (PMIA) fibre is a kind of aromatic polyamide fibre, which can be prepared by a wet-spinning method. In this work, the process conditions of spinning influenced the performance and structure of the coloured PMIA fibre, and these conditions included spinning speed, coagulation bath, etc. Because the diffusion coefficient was associated with the performance and structure, the ratio of solvent to coagulant could explain the reason of influence of the coagulation bath on the fibre. In this study, PMIA spinning dopes with Colour Inde Blue 60 were first commixed in a pressurizer and then spun into a coagulation bath under a pressure of around 0.3 MPa. At a coagulation bath temperature of 50 °C, pure or dope-dyed PMIA fibres were prepared by wet spinning, and then the spun fibres were extracted by an ultrasonic oscillation method. The effect of the jet stretch ratio and the temperature and concentration of coagulation bath on the ratio of diffusion coefficient of solvent to coagulator were analysed during spinning process of dope-dyed PMIA fibres. The properties and structures of coloured PMIA fibres were characterized by SEM. Finally the optimized spinning technology of the dope-dyed PMIA fibre was obtained.