Dry jet-wet spinning of strong cellulose filaments from ionic liquid solution

Abstract

Considerable growth is expected in the production of man-made cellulose textile fibers, which are commercially produced either via derivatization to form cellulose xanthate (viscose) or via direct dissolution in N-methylmorpholine N-oxide (Lyocell). In the study at hand, cellulosic fibers are spun from a solution in the ionic liquid [DBNH] [OAc] into water, resulting in properties equal or better than Lyocell (tensile strength 37 cN tex -1 or 550 MPa). Spinning stability is explored, and the effects of extrusion velocity, draw ratio, spinneret aspect ratio and bath temperature on mechanical properties and orientation are discussed. With the given set-up, tenacities and moduli are improved with higher draw ratios, while elongation at break, the ratio of wet to dry strength, modulus of resilience and birefringence depend little on draw ratio or extrusion velocity, elastic limit not at all. We find the process robust and simple, with stretching to a draw ratio of 5 effecting most improvement, explained by the orientation of amorphous domains along the fiber axis.

High‐Strength Composite Fibers from Cellulose–Lignin Blends Regenerated from Ionic Liquid Solution

“…[14] TGA TGA was performed by using aPerkinElmer TGA7 Thermogravimetric Analyser.T he analysis was performed under an itrogen atmosphere to avoid the oxidation of the materials. The settings for the Vibrodyn 400 were:g auge length 20 mm, strain rate 20 mm min À1 and pre-tension (5.9 AE 1.2) mN tex À1 .T en fibres of each sample were measured.…”

“…[10,11] As ar esult of the presence of lignin and hemicellulose, the properties of the resulting fibres are inferior to that from pure dissolvingp ulps. [14] This results in ah ighly stable process with basically no degradation of either the solvent or the cellulose. [11] Recently, we introduced the IL 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH][OAc]) as an excellent direct cellulose solvent, which revealed ah igh spinning stabilityo ft he respective solutions, and the obtained regenerated cellulose fibres showed outstanding fibre properties.…”

Processing of Cellulose Using Ionic Liquids

“…Apart from several ILs of the imidazolium family, a spinning process based on the so called Ionocell process, which uses [DBNH][OAc], was developed by Sixta et al . This process is close to industrial conversion, since garments like ties or shirts are already produced, finished, and dyed .…”

“…[44] An appropriate IL-system, [EMIM][OAc] was proposed for wet spinning of cellulose, including details on the rheology of the spinning dopes, characterization of the fiber, and the recycling of ILs. [29] Apart from several ILs of the imidazolium family, a spinning process based on the so called Ionocell process, which uses [DBNH][OAc], was developed by Sixta et al [21,22,[45][46][47] This process is close to industrial conversion, since garments like ties or shirts are already produced, finished, and dyed. [21] Several important parameters like the influence of pulp source, degree of polymerization, the mass distribution, as well as process parameters like the draw ratio, the air gap size, and the temperature of the coagulation bath were studied.…”

Assembly of metal nanoparticles on regenerated fibers from wood sawdust and de-inked pulp: flexible substrates for surface enhanced Raman scattering (SERS) applications

“…The regenerated sawdust and DIP fibers were provided by the Biorefineries Research Group at the Department of Forest Products Technology, Aalto University School of Chemical Technology (Hauru et al 2014). Water used in all experiments was deionized and further purified by a Millipore Synergy UV Unit to a resistivity *18.2 MX cm.…”