Cellulose long fibers fabricated from cellulose nanofibers and its strong and tough characteristics

Abstract

Cellulose nanofiber (CNF) with high crystallinity has great mechanical stiffness and strength. However, its length is too short to be used for fibers of environmentally friendly structural composites. This paper presents a fabrication process of cellulose long fiber from CNF suspension by spinning, stretching and drying. Isolation of CNF from the hardwood pulp is done by using (2, 2, 6, 6-tetramethylpiperidine-1-yl) oxidanyl (TEMPO) oxidation. The effect of spinning speed and stretching ratio on mechanical properties of the fabricated fibers are investigated. The modulus of the fabricated fibers increases with the spinning speed as well as the stretching ratio because of the orientation of CNFs. The fabricated long fiber exhibits the maximum tensile modulus of 23.9 GPa with the maximum tensile strength of 383.3 MPa. Moreover, the fabricated long fiber exhibits high strain at break, which indicates high toughness. The results indicate that strong and tough cellulose long fiber can be produced by using ionic crosslinking, controlling spinning speed, stretching and drying.

Poly(vinyl alcohol)–lignin blended resin for cellulose‐based composites

“…Because of dimensional limitations, however, nanocellulose is normally used as fillers for polymer composites . In recent years, nanocellulose‐based long fibers have been investigated to overcome the dimensional limitations of nanocellulose …”

Effect of Wet Spinning and Stretching to Enhance Mechanical Properties of Cellulose Nanofiber Filament

“…To fabricate CNF filaments, firstly, a wet-state CNF filament (WCF) was prepared by using the wet spinning with ion exchange [15]. The wet spinning process has three steps: coagulation, pre-drying and washing.…”

“…In the wet spinning process, the filament of the raw polymer material is formed by the diffusional interchange between filament and coagulation solution [7]. In the previous researches, wet spun filaments were made from various raw materials such as graphene oxide [8], agar [9], polyvinylidene difluoride [10] and cellulose [11][12][13][14][15] in various kinds of coagulation solutions; acetone [11][12][13], ethanol [14], calcium chloride [15].…”

“…However, they consume high energy and cost a lot for process setup compared with mechanical stretching. According to previous researches, various attempts of wet stretching were reported to form long filaments, including wet-stretching method progressed in wet solution [20], zone stretching method using two different roller speed ratio [21], cold drawing using tensile test machine at the room temperature [22] and simply physical stretching using shifting device [15]. In wet stretching, several parameters such as spinning speed, inner diameter of needle and dry temperature influence the results in terms of alignment of CNFs and hydrogen bonds between CNFs.…”

Esterified PVA‐lignin resin by maleic acid applicable for natural fiber reinforced composites

“…NC has been well recognized as reinforcing materials of polymer composites . Moving away from the use of NC as reinforcing materials, once NC is utilized for long filament that can maintain the superior mechanical properties of NC, then the NC‐based filament can be used for strengthening natural fiber reinforced polymers (NFRP) composites, which are environment‐friendly and high strength composites . Figure shows the concept of the proposed environment‐friendly and high‐strength NFRP composite.…”