The Effects of Polyethylene Glycol on the Spinnability of Dry-jet Wet Spinning Heterocycle Aramid Fiber

The spinnability of semi-dilute poly(p-phenylene-benzimidazole-terephthamide) (PBIA) spinning solution was regulated by a small amount of polyethylene glycol (PEG) to make it suitable for dry-jet wet spinning. The effects of different molecular weights and contents of PEG on the rheological properties and spinnability of PBIA spinning solution were investigated. Results show that the PBIA spinning solution with PEG 50,000 has the highest viscosity and the best spinnability, which can be smoothly spun by dry-jet wet spinning. The dynamic viscoelasticity study shows that the energy storage modulus and loss modulus of the PBIA spinning solution keeps increasing with PEG 50,000 and achieves the maximum value of 0.5% wt. The maximum draw ratio between the first roll and the spinneret (D_m) also reached a maximum value of 3.0 when the addition of PEG 50,000 reached 0.5% wt. Moreover, primary PBIA fibers prepared by dry-jet wet spinning and a higher draw ratio have a smoother surface appearance and better mechanical properties.