			Home About us Contact

Lyocell Fibers (lyocell + fiber)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Influence of hemicelluloses on the structure and properties of Lyocell fibers

POLYMER ENGINEERING & SCIENCE, Issue 5 2007
Huiru Zhang
In the present paper the difference in the structure and properties of Lyocell fibers with different hemicelluloses content was investigated. The supermolecular structure and the morphological characterization were compared. The fibril aggregation size was estimated by the cross-polarization magic-angle spinning carbon-13 nuclear magnetic resonance (CP/MAS13C-NMR) spectroscopy. Meanwhile, the difference in the mechanical, the fibrillation resistance and the dyeing properties of Lyocell fiber with different hemicelluloses content was also analyzed. POLYM. ENG. SCI., 47:702,706, 2007. © 2007 Society of Plastics Engineers. [source]

Preparation and properties of the single-walled carbon nanotube/cellulose nanocomposites using N -methylmorpholine- N -oxide monohydrate

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010
Dong-Hun Kim
Abstract Single-walled carbon nanotube (SWNT)/cellulose nanocomposite films were prepared using N -methylmorpholine- N -oxide (NMMO) monohydrate as a dispersing agent for the acid-treated SWNTs (A-SWNTs) as well as a cellulose solvent. The A-SWNTs were dispersed in both NMMO monohydrate and the nanocomposite film (as confirmed by scanning electron microscopy) because of the strong hydrogen bonds of the A-SWNTs with NMMO and cellulose. The mechanical properties, thermal properties, and electric conductivity of the nanocomposite films were improved by adding a small amount of the A-SWNTs to the cellulose. For example, by adding 1 wt % of the A-SWNTs to the cellulose, tensile strain at break point, Young's modulus, and toughness increased , 5.4, , 2.2, and , 6 times, respectively, the degradation temperature increased to 9°C as compared with those of the pure cellulose film, and the electric conductivities at , (the wt % of A-SWNTs in the composite) = 1 and 9 were 4.97 × 10,4 and 3.74 × 10,2 S/cm, respectively. Thus, the A-SWNT/cellulose nanocomposites are a promising material and can be used for many applications, such as toughened Lyocell fibers, transparent electrodes, and soforth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Thermostability of Lyocell Dopes Modified with Surface-Active Additives

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 8 2005
Frank Wendler
Abstract Summary: Cellulose/N -methylmorpholine- N -oxide monohydrate (NMMO) spinning solutions were modified with surface-active additives to yield Lyocell fibers with functional properties. Based on cellulose fibers, a new class of materials with tailored adsorption characteristics are produced. Activated charcoal and carbon black used as additives significantly affect the thermostability of the spinning solutions. Considering the degree of filling three general tendencies become evident. It is most obvious that the onset temperature of dope decomposition is shifted towards lower values accompanied by viscosity reduction after annealing at elevated temperatures and an enhanced formation of degradations products. Morpholine, N -methylmorpholine and formaldehyde as the main degradation products were detected in aqueous distillates by means of HPLC. To study the rate of by-product formation during preparation of the solution kinetic measurements were carried out. Thermal instabilities are not only initiated by heavy metal ions, especially Fe(II), but also by the particle size and porosity of the charcoal. The nano-scaled carbon black used causes autocatalytic reactions as revealed by calorimetric measurements. Relationships between amount of Acc versus onset temperature (Ton) and concentration of N -methylmorpholine. [source]