Effect of draw-ratio on the structure and properties of wet-spun cyanoethyl cellulose fibers

Abstract

Cyanoethyl cellulose (CEC) with a degree of substitution (DS) of 2.77 was dissolved in DMSO, and the resulting solution was used to prepare high wet strength fibers on a homemade wet-spinning device. The CEC and corresponding fibers were characterized with FT-IR, ¹H and ¹³C NMR, rheological measurements, SEM, AFM, XRD, SAXS, tensile tests, and dielectric spectroscopy. The CEC solution had a shear thinning behavior as a common non-Newtonian fluid. Coagulation of CEC using a mixture of H₂O and DMSO (3:1) resulted in fibers with a glossy surface, circular cross-section, and compact core structure. With the draw ratio used to prepare the fibers increased from 1.03 to 1.79, the orientation parameters of CEC fibers determined by 2D WAXD increased slightly from 0.56 to 0.61. In the dry state, the tensile strength of the CEC fibers increased from 2.22 to 2.73 cN dtex⁻¹, the elongation at break decreased from 43.7 to 31.5%, and the elastic modulus increased from 52 to 69 cN dtex⁻¹, respectively. Attributed to the introduction of polar cyanoethyl groups, CEC fibers displayed excellent mechanical properties in the wet state. The tensile strength increased from 2.16 to 2.68 cN dtex⁻¹, the elongation at break decreased from 43.9 to 32.8%, and the elastic modulus increased from 36 to 53 cN dtex⁻¹ with increasing draw ratio, respectively. It is worth noting that the tensile strength of CEC fibers in the wet state can still maintain more than 90% of those in dry state. Moreover, the CEC non-woven fabrics and film all displayed dielectric properties, suggesting these materials have application prospects in electronic components and textiles.