Structure and Properties of Regenerated Cellulose Filaments Prepared from Cellulose Carbamate–NaOH/ZnO Aqueous Solution

Abstract

In this work, regenerated cellulose (RC) filaments were successfully spun from cellulose carbamate in a NaOH/ZnO aqueous solution on a pilot scale. The structure and properties of the RC filaments were characterized using SEM, FT-IR, elemental analysis, 13C NMR, XRD, 2D WAXD, tensile testing, and dye testing. The nitrogen-free and sulfur-free RC filaments exhibited a bright surface and circular cross section. The filaments demonstrated a typical cellulose II crystal structure and a relatively high degree of orientation. Improved tenacity and structure were obtained in the RC fibers due to improved post-processing spinning steps and an increased drawing ratio. The tenacity of the fibers was determined in the range of 1.69–2.36 cN/dtex, which was comparable with that of commercial viscose rayon. Furthermore, the RC filaments showed improved dye properties compared with viscose rayon. The described carbamate pathway provided a simple and environmentally friendly method, offering an alternate to the environmental drawbacks of the viscose process.