Preparation of High-Performance Polyethersulfone/Cellulose Nanocrystal Nanocomposite Fibers via Dry-Jet Wet Spinning

Abstract

Polyethersulfone (PES) and PES/cellulose nanocrystal (CNC) nanocomposite fibers were prepared via dry-jet wet spinning at the filler loading of 1 and 2 wt%. Prior to the spinning, the optimal dispersion time of CNC in N, N-dimethylacetamide was investigated based on the dynamic light scattering. Upon the bath-type sonication, the hydrodynamic diameter (Dh) of CNCs was reduced sharply from 1281 to 37.8 nm up to the dispersion time of 48 h, indicating the well-dispersed nature of the individual CNC molecules. After 48 h, the Dh of CNC plateaued in the range of 28.2–43.8 nm, and therefore, the optimal sonication time was set to 48 h. The tensile properties of dry-jet wet-spun PES fibers were significantly affected by the post-drawing temperature. Over the range of 80–120 °C, the 100 °C-drawing resulted in the highest tensile properties of the fibers. At a total draw ratio of 8, the control PES fibers exhibited the tensile strength of 230 MPa, modulus of 4.0 GPa, and toughness of 36.4 J/g, while PES/CNC1 fibers showed 240 MPa, 4.7 GPa, and 51.8 J/g, respectively. On the contrary, the incorporation of 2 wt% CNC led to diminished tensile properties due to the inhomogeneity of the spinning dope as confirmed by the rheological analysis.