Ioncell-F: ionic liquid-based cellulosic textile fibers as an alternative to viscose and Lyocell

Abstract

Ioncell-F, a recently developed process for the production of man-made cellulosic fibers from ionic liquid solutions by dry-jet wet spinning, is presented as an alternative to the viscose and N-methylmorpholine N-oxide (NMMO)-based Lyocell processes. The ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate was identified as excellent cellulose solvent allowing for a rapid dissolution at moderate temperatures and subsequent shaping into continuous filaments. The highly oriented cellulose fibers obtained upon coagulation in cold water exhibited superior tenacity, exceeding that of commercial viscose and NMMO-based Lyocell (Tencel®) fibers. The respective staple fibers, which have been converted into two-ply yarn by ring spinning technology, presented very high tenacity. Furthermore, the Ioncell yarn showed very good behavior during the knitting and weaving processes, reflecting the quality of the produced yarn. The successfully knitted and woven garments from the Ioncell yarn demonstrate the suitability of this particular ionic liquid for the production of man-made cellulosic fibers and thus give a promising outlook for the future of the Ioncell-F process.

Influence of molar mass distribution on the final properties of fibers regenerated from cellulose dissolved in ionic liquid by dry-jet wet spinning

“…For comparison purposes, the eucalyptus prehydrolysis kraft pulp was spun at similar conditions. Its good spinnability and ability to be converted to cellulose filament has been proven earlier [16,22]. Consequently, the intrinsic characteristics of this pulp and the resulting fiber properties represented a benchmark in this study.…”

“…The spinning temperatures for each [DBNH]OAc solution were determined according to the zero-shear viscosity and are summarized in Table 2. According to previous studies [16,22], a value of 30000 Pa s was chosen as reference.…”

“…The Ioncell-F(iber) process, employing ILs as cellulose solvent, is a recently developed process presented as an alternative to the currently common viscose and Lyocell processes for the production of MMCFs [16,22]. The Ioncell-F process utilizes the same technique as the NMMO process and is thus also classified as a Lyocell-type process.…”

Homogenous esterification of cellulose pulp in [DBNH][OAc]

“…[DBNH][OAc] is a robust solvent for cellulose and pulp, recycled paper and even cotton, e.g., used cotton clothes. Further, high quality cellulosic textile fibers can be produced from cellulose [DBNH][OAc] solutions by spinning thin filaments into an antisolvent, as in IONCELL-F process (Michud et al 2016;Sixta et al 2015). Therefore, [DBNH][OAc] is also of interest as a reaction medium, as the same solvent and process could be used to obtain chemically modified cellulosic fibers or materials.…”

“…One of these is [DBNH][OAc], which is not only an efficient solvent for cellulose, but high-quality textile fibers can be produced upon regeneration of cellulose solutions into water (IONCELL-F process) (Michud et al 2016;Parviainen et al 2013Parviainen et al , 2015Sixta et al 2015). Therefore, it would be highly beneficial to control the modification to cellulose esters before regeneration to fibers (for textile and non-wovens) or films.…”