Structures and Mechanical Properties of Cellulose Filament Spun from Cellulose/Aqueous NaOH Solution System

Abstract

ABSTRACT:An attempt was made to disclose super-molecular structure and mechanical properties of new cellulose filament prepared from cellulose-aqueous alkali solution system. X-Ray crystallinity index Xc(X) of the new cellulose filament was far higher than those of other commercial rayons, such as viscose including polynosic and cupro and was slightly lower than the organic spun rayon. The new cellulose filament showed the lowest degree of crystal orientation among these three kinds of cellulose fibers, because of its lowest draft and stretching ratio during the spinning process. In the new filament degree of the intramolecular hydrogen bondings (I -Xam(C 3)) estimated by 13 C NMR method was highly developed. The mechanical loss tangent (tan '5) vs. temperature T curves of the new filament exhibited C( relaxation (from higher temperature side; 0( 2 , C(,h) attributed to micro-Brownian motion of the cellulose chains, two {3 ({3.1, {3. 2 ), local mode of the chains, and y, rotational mode of primary alcohol group at C6 position of pyranose rings, in the regions of T=250--100°C and -30--100°C, and near -I 00°C, respectively. Judging from the co relationships of these relaxation peak temperature T max to Xc(X) and I -Xam(C3), we concluded that there exist two amorphous regions with well-developed intramolecular hydrogen bonds but less advanced intermolecular hydrogen bonds and vice-versa in the new filament. The results of thermally stimulated currency (TSC) measurements suggested that the hydrophobic interaction among cellulose chains is tightly formed in the region with the well-developed intramolecular hydrogen bonds. In this regard, XTSc peak named here was found to correspond to mechanical relaxation C(sh· The tensile strength and elongation of the new filament were comparable to those of the regular viscose rayon. The new filament showed less swelling ratio and low fibrillation nature in water. Woven fabrics made from the filament gave some softness and high abrasion, compared with other commercial ones and were hard to wrinkle.KEY WORDS Alkali Soluble Cellulose / Filament / Supermolecular Structure / X-Ray Crystallinity / Intramolecular Hydrogen Bonds/ Viscoelastic Properties/ Mechanical Properties/ Woven Fabrics/ Authors have already established an improved cellulose dissolving technology (two step slurry method) using so-called steam-exploded pulp with average particle size of ca. 10 µm and aqueous (aq) sodium hydroxide (NaOH) solution with total concentration of ca. 7.6 wt¾, 1 based on the discovery that exploded pulp could be dissolved into aq NaOH with a specific concentration. 2 -4 In addition, all sulfite pulp, of which the degree of intramolecular hydrogen bond is always lowered by steam-explosion, has been proved to be useful as industrial resource for the above usage. 5 On the basis of the above technology authors have succeeded in manufacturing a new cellulose filament by establishing the industrially meaningful wet-spinning method (that is, the net-process where no spinning tension generates theo...

Structure and Properties of Cellulose-Starch Blend Films Regenerated from Aqueous Sodium Hydroxide Solution

“…NaOH solution has the mechanical properties comparable to commercially available regenerated cellulose fibers (Yamane et al, 1996a). From a technical viewpoint, regenerated cellulose fibers with good mechanical properties for textile use have been produced in a bench-scale pilot plant (Yamane et al, 1996b(Yamane et al, , 1996c.…”

Comparison between Cellulose Blend Films Prepared from Aqueous Sodium Hydroxide Solution and Edible Films of Biopolymers with Possible Application for New Food Materials

“…The cellulose fiber regenerated from aq. NaOH solution has the mechanical properties comparable to commercially available regenerated cellulose fibers (Yamane et al, 1996a). From a technological perspective, cellulose fiber regenerated from this dissolving system can be produced for textile use using bench-scale equipment (Yamane et al, 1996b).…”

Effects of Hydrophobic Solvents on X-Ray Diffraction Patterns of Regenerated Cellulose Membrane

“…The molecular sheet-like assembly (corresponding to sh relaxation), proposed previously by Yamane et al [Polym. J., 28, 1039(1996] may be a plausible explanation of the result. Analysis of X-Ray diffraction intensity of cellulose/solvent systems might give some information on the extent of interaction between cellulose and solvent in question.…”

“…170 C to less than room temperature 9 and 2) such solvents might induce concentration-specific mobilization of cellulose chains. Therefore, more detailed studies on the interaction of cellulose with nonpolar solvents are immediately required.…”