From Regenerated Wood Pulp Fibers to Cationic Cellulose: Preparation, Characterization and Dyeing Properties

Abstract

The global demand for sustainable textile fibers is growing and has led to an increasing research interest from both academia and industry to find effective solutions. In this research, regenerated wood pulp fibers were functionalized with glycidyltrimethylammonium chloride (GTAC) to produce modified regenerated cellulose with cationic pending groups for improved dye uptake. The resultant cationic cellulose with a degree of substitution (DS) between 0.13 and 0.33 exhibited distinct morphologies and contact angles with water ranging from 65.7° to 82.5° for the fibers with DS values of 0.13 and 0.33, respectively. Furthermore, the thermal stability of the modified regenerated cellulose fibers, albeit lower than the pristine ones, reached temperatures up to 220 °C. Additionally, the modified fibers showed higher dye exhaustion and dye fixation values than the non-modified ones, attaining maxima values of 89.3% ± 0.9% and 80.6% ± 1.3%, respectively, for the cationic fibers with a DS of 0.13. These values of dye exhaustion and dye fixation are ca. 34% and 77% higher than those obtained for the non-modified fibers. Overall, regenerated wood pulp cellulose fibers can be used, after cationization, as textiles fiber with enhanced dye uptake performance that might offer new options for dyeing treatments.

Functional fibers from regenerated wood pulp cellulose and a natural‐based phytate with enhanced flame retardancy properties

“…The surface wetting behavior of the unmodified and modified CellReg fibers was analyzed by static WCA measurements, as summarized in Table 2. Predictably, the unmodified CellReg fibers presented the lowest WCA value of 55.5 ± 4.2°, analogously to the data available in the literature for regenerated cellulose from cotton linters using different ionic liquids as solvents 35 and regenerated cellulose from wood pulp fibers dissolved in MTBD‐acetate 32 . In relation to the modified CellReg fibers (Table 2), the WCA increased from 77.1 ± 9.4° for CellReg/PAA1 to 87.0 ± 8.2° for CellReg/PAA2 and 91.9 ± 8.6° for CellReg/PAA3.…”

“…The surface charge of the unmodified and modified CellReg fibers was evaluated by zeta potential measurements. Table 2 shows that CellReg has a negative apparent zeta potential (ζ) value of −17.4 ± 3.7 mV (pH 7), due to the presence of carboxyl and hydroxyl groups, 41,42 in line with, for example, the value registered for Lyocell fibers of about −15 mV (at pH 7) 43 and for regenerated cellulose from wood pulp fibers dissolved in MTBD‐acetate (ζ = −15.4 ± 5.0 at pH 7) 32 . After modification, the surface charge became more negative than CellReg with apparent zeta potential values of −31.8 ± 4.3 mV for CellReg/PAA1, −35.4 ± 5.0 mV for CellReg/PAA2 and − 38.2 ± 5.4 mV for CellReg/PAA3, although the values are not significantly different among the modified samples.…”

“…Cellulose fibers with improved flame retardancy were prepared through the heterogeneous modification of regenerated cellulose (CellReg) with a phytic acid derivative (PAA) containing phosphate ester moieties (Figure 1a). The CellReg fibers (obtained via dissolution in an ionic liquid followed by regeneration in water) were selected because of their biodegradability, lower CO 2 footprint, low density, homogeneous morphological, mechanical and physical properties, and high reactivity, 8,32 whereas the PAA is derived from a wellknown natural halogen-free flame-retardant. 25 Three different concentrations of PAA were tested to obtain fibers with different contents of the phosphorus-containing flame-retardant.…”

“…Table 2 shows that CellReg has a negative apparent zeta potential (ζ) value of À17.4 ± 3.7 mV (pH 7), due to the presence of carboxyl and hydroxyl groups, 41,42 in line with, for example, the value registered for Lyocell fibers of about À15 mV (at pH 7) 43 and for regenerated cellulose from wood pulp fibers dissolved in MTBDacetate (ζ = À15.4 ± 5.0 at pH 7). 32 After modification, the surface charge became more negative than CellReg with apparent zeta potential values of À31.8 ± 4.3 mV for CellReg/PAA1, À35.4 ± 5.0 mV for CellReg/PAA2 and À 38.2 ± 5.4 mV for CellReg/PAA3, although the values are not significantly different among the modified samples. The variation in the surface charge of CellReg after modification with PAA suggests the occurrence of the functionalization, which is coherent with the ζ values observed by Duel et al 44 for phytate-coated Fe 3 O 4 nanoparticles and by Chen et al 45 for scheelite and calcite coated with sodium phytate.…”

“…Predictably, the unmodified CellReg fibers presented the lowest WCA value of 55.5 ± 4.2 , analogously to the data available in the literature for regenerated cellulose from cotton linters using different ionic liquids as solvents 35 and regenerated cellulose from wood pulp fibers dissolved in MTBD-acetate. 32 In relation to the modified CellReg fibers (Table 2), the WCA increased from 77.1 ± 9.4 for Cell-Reg/PAA1 to 87.0 ± 8.2 for CellReg/PAA2 and 91.9 ± 8.6 for CellReg/PAA3. These results attest that the functionalization with PAA raised the hydrophobicity of the modified CellReg fibers, even though remaining in the limit that separates the hydrophilic range (10 < θ < 90 ) from the hydrophobic scale (90 < θ < 150 ).…”