High Modulus Regenerated Cellulose Fibers Spun from a Low Molecular Weight Microcrystalline Cellulose Solution

We have developed a novel process to convert low molecular weight microcrystalline cellulose into stiff regenerated cellulose fibers using a dry-jet wet fiber spinning process. Highly aligned cellulose fibers were spun from optically anisotropic microcrystalline cellulose/1-ethyl-3-methylimidazolium diethyl phosphate (EMImDEP) solutions. As the cellulose concentration increased from 7.6 to 12.4 wt %, the solution texture changed from completely isotropic to weakly nematic. Higher concentration solutions (>15 wt %) showed strongly optically anisotropic patterns, with clearing temperatures ranging from 80 to 90 °C. Cellulose fibers were spun from 12.4, 15.2, and 18.0 wt % cellulose solutions. The physical properties of these fibers were studied by scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD), and tensile testing. The 18.0 wt % cellulose fibers, with an average diameter of ∼20 μm, possessed a high Young’s modulus up to ∼22 GPa, moderately high tensile strength of ∼305 MPa, as well ...