scholarly journals New Solvent and Coagulating Agent for Development of Chitosan Fibers by Wet Spinning

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2121
Author(s):  
Ghasem Mohammadkhani ◽  
Sunil Kumar Ramamoorthy ◽  
Karin Adolfsson ◽  
Amir Mahboubi ◽  
Minna Hakkarainen ◽  
...  

Adipic acid was evaluated as a novel solvent for wet spinning of chitosan fibers. A solvent with two carboxyl groups could act as a physical crosslinker between the chitosan chains, resulting in improved properties of the fibers. The performance of adipic acid was compared with conventional solvents, i.e., lactic, citric, and acetic acids. Chitosan solutions were injected into a coagulation bath to form monofilaments. Sodium hydroxide (NaOH) and its mixture with ethanol (EtOH) were used as coagulation agents. Scanning electron microscopy confirmed the formation of uniform chitosan monofilaments with an even surface when using adipic acid as solvent. These monofilaments generally showed higher mechanical strength compared to that of monofilaments produced using conventional solvents. The highest Young’s modulus, 4.45 GPa, was recorded for adipic acid monofilaments coagulated in NaOH-EtOH. This monofilament also had a high tensile strength of 147.9 MPa. Furthermore, taking advantage of chitosan insolubility in sulfuric acid (H2SO4) at room temperature, chitosan fibers were successfully formed upon coagulation in H2SO4-EtOH. The dewatering of fibers using EtOH before drying resulted in a larger fiber diameter and lower mechanical strength. Adipic acid fibers made without dehydration illustrated 18% (for NaOH), 46% (for NaOH-EtOH), and 91% (for H2SO4-EtOH) higher tensile strength compared to those made with dehydration.

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 570 ◽  
Author(s):  
Zhihui Zhao ◽  
Cunzhen Geng ◽  
Xihui Zhao ◽  
Zhixin Xue ◽  
Fengyu Quan ◽  
...  

Fluorescent textile fibres (FTFs) are widely used in many industrial fields. However, in addition to fibres with good fluorescence, fibres with excellent colour controllability, structural stability and appropriate mechanical strength still need to be developed. In this work, CdTe/alginate composite FTFs are prepared by taking advantage of the interactions between CdTe nanocrystals (NCs) and alginate macromolecules via a wet-spinning machine with a CaCl2 aqueous solution as the coagulation bath. CdTe NCs were chemically fixed in the fibre due to the interactions among surface ligands, macromolecules and coagulators (calcium ions), which ensured the excellent dispersity and good stability of the fibres. Förster resonance energy transfer (FRET) between NCs in the fibre was found to be restricted, which means that the emission colour of the fibres was totally controllable and could be predicted. Other properties of alginate fibres, such as flame retardance and mechanical strength, were also well preserved in the fluorescent fibres. Finally, FTFs showed good selectivity toward trace Hg2+ ions over other metallic ions, and the detection could be identified by the naked eye.


2013 ◽  
Vol 652-654 ◽  
pp. 1562-1565 ◽  
Author(s):  
Jing Guo ◽  
Qian He Chen ◽  
Yu Yan Zhang ◽  
Yu Mei Gong ◽  
Hong Zhang

Alginate/polyvinyl alcohol (PVA) composite fibers containing copper ions were prepared by wet spinning. The spinning solution and manufacturing process were researched. The composite fibers were characterized by Tensile Strength Tester, SEM and TGA. This report shows that the spinning solution is a typical kind of pseudoplastic fluid. Adding boric acid to coagulation bath and putting Cu ions into composite fibers can improve the strength. The structure of composite fibers with Cu ions is denser and there are grooves on the fiber surface. In addition, the thermal property of composite fibers is steady.


2011 ◽  
Vol 175-176 ◽  
pp. 272-275 ◽  
Author(s):  
Lin Liu ◽  
Ju Ming Yao

In this paper, the cellulose whisker/silk fibroin (CW/SF) aqueous solution with different composition was obtained by a dialysis against polyethylene glycol (PEG) solution at room temperature. The rheological behavior of CW/SF solution was investigated and the reinforced CW/SF hybrid fibres were prepared by a dry-wet spinning method. The results showed that the spinnability was better for the CW/SF solution according to the calculation of flowing characteristic index. The cellulose whiskers were dispersed homogeneously in the silk matrix. Moreover, it could be found that the tensile strength and Young’s modulus of the hybrid fibers were improved with the increase of cellulose whisker content, which reached the maximum when the cellulose whisker content was 5 wt%. Compared with the pure silk fiber, the tensile strength and Young’s modulus of the CW/SF hybrid fibers containing 5 wt% CWs were increased from 135.78±12.73 MPa and 5.74±0.43 GPa to 438.68±22.63 MPa and 17.36±2.04 GPa, respectively.


2020 ◽  
Vol 869 ◽  
pp. 266-272
Author(s):  
Gleb Vaganov ◽  
Andrei Didenko ◽  
Elena Ivan’kova ◽  
Elena Popova ◽  
Vladimir Elokhovskii ◽  
...  

A polyamide acid (PAA) based on diamine 4,4'-bis (4-aminophenoxy) diphenyl and 1,3-bis (3',4-dicarboxyphenoxy) benzene dianhydride was synthesized. PAA fibers were obtained by wet spinning. Then, these fibers were converted into polyimide by thermal imidization. Dependence of the structure and properties of fibers on the die drawing and the composition of the coagulation bath was studied. It is shown that the composition of the coagulation bath has a significant effect on the morphology and mechanical properties of polyimide (PI) fibers. To obtain defect-free fibers, a coagulation bath consisting of ethylene glycol/ethanol at 50/50 vol. % was found to be optimal. An increase in the die drawing of fibers from 1 to 2 times leads to an increase in tensile strength and strain at break of the polyimide fibers.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1909
Author(s):  
Khoa Dang Nguyen

Chitin was chemically extracted from crab shell waste and dissolved in N,N-dimethyl acetamine/5% lithium chloride (DMAc/5% LiCl) at room temperature to obtain 1% and 2% concentrations of chitin solution. Chitin fibers were prepared by phase inversion at different temperatures of water coagulation bath at 5, 20, and 60 °C. The deconvolution of FTIR spectra indicated that the area portion of the intermolecular hydrogen bonding NH…OC increased at 60 °C due to the higher density of the chitin segment in the fiber. As a result, scanning electron microscope (SEM) measurement suggests that a denser structure of the chitin fiber was observed when the temperature of the coagulation bath increased. In addition, the resultant chitin fibers generated better mechanical properties relative to the amount of chitin concentration and temperature. At 2% of chitin solution, the tensile strength significantly increased from 80 to 182 MPa for the fiber obtained at temperatures of 5 and 60 °C of the water coagulation bath, respectively. Meanwhile, the water content in the fiber significantly decreased from 1101% to 335%. This green synthesis route has high potential for the fabrication of the fiber as future material of interest for biomedical application.


2017 ◽  
Vol 5 (32) ◽  
pp. 16889-16897 ◽  
Author(s):  
Youhao Zhang ◽  
Li Yuan ◽  
Qingbao Guan ◽  
Guozheng Liang ◽  
Aijuan Gu

A novel multi-functional polyacrylate coating simultaneously showing high tensile strength, good reversible self-healing efficiency and remarkable antibacterial ability has been developed.


2011 ◽  
Vol 284-286 ◽  
pp. 1271-1274 ◽  
Author(s):  
Li Xia Zhu ◽  
Xiao Dong He ◽  
Xin Li Han ◽  
Ting Ting Qu

The morphological changes, dimension and distribution of M/A constituent in different region of X80 acicular ferrite pipeline steel were investigated; the effect of M/A constituents of X80 on Charpy V-impact and room temperature tensile properties were also discussed by OM and SEM. The results show that: the distribution and morphosis of the M/A constituents have strongly effect on the mechanical properties. The uniformly distributed massive M/A constituents with chord less than 2 μm observed in grains of base metal, presents high impact toughness and high tensile strength, and the strip M/A constituents with chord more than 2 μm observed in welded joint samples exhibits low impact toughness and high tensile strength. It is seems that the changes of the morphosis and distribution of M/A constituents induce the hardening effect during the deformation which is the main reason to the different mechanical property.


Alloy Digest ◽  
1965 ◽  
Vol 14 (8) ◽  

Abstract SAP is a special Sintered Aluminum Powder characterized by high tensile strength at room temperature and at elevated temperatures. It features a range of useful engineering properties. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, joining, and powder metal forms. Filing Code: Al-146. Producer or source: Aluminium Industrie Atkiengesellschaft.


2007 ◽  
Vol 561-565 ◽  
pp. 395-398 ◽  
Author(s):  
N. Matsumoto ◽  
Yasuyuki Kaneno ◽  
Takayuki Takasugi

Zr and/or Nb added Fe3Al based intermetallic alloys (i.e., Fe3Al-Zr, Fe3Al-Nb and Fe3Al-Zr-Nb) were arc-melted, homogenized, hot-rolled and then annealed to evaluate microstructure and tensile property at room temperature as well as at a high temperature (873K). After annealing, the rolled alloys exhibited a recrystallized microstructure containing coarse second phase particles, except for the Nb-added alloy with a minor content of Nb. Relatively high tensile elongation as well as high tensile strength was observed at room temperature in the Zr-added alloys with a minor amount of Zr. Also, these alloys showed relatively high tensile strength and elongation at high temperature (873K). The results suggest that tensile ductility as well as strength of Fe3Al-based alloys can be improved by introduction of the second phase dispersions.


2006 ◽  
Vol 319 ◽  
pp. 139-144 ◽  
Author(s):  
Masuyuki Hasegawa ◽  
M. Takeuchi ◽  
D. Nagata ◽  
T. Wada ◽  
Hidemi Kato ◽  
...  

The hydrogen-induced internal friction and mechanical strength of the Ti-rich Ti34Zr11Cu47Ni8 and (Ti34Zr11Cu47Ni8)98Si2 hydrogenated glassy alloys have been investigated. It is found that the tensile strength is more than 0.8 GPa at room temperature when the hydrogen content is below about 20 at% for both alloys. The frequency dependence of peak temperature of the hydrogen-induced internal friction of (Ti34Zr11Cu47Ni8)98Si2-17.3 at%H hydrogenated glassy alloys has been clarified. Activation energy and pre-exponential factor are estimated to be 0.35 eV and 1.3x10-12, respectively. Compared with these values with those of Zr40Cu49Al10Si1 hydrogenated glassy alloys which show an internal friction peak around 300 K at about 300 Hz, it is found that the activation energy is much smaller than that of the latter although the pre-exponential factor is almost the same. Considering their similar composition and different component (Al), it is suggested that the component Al of the latter glassy alloys is effective for the higher activation energy which results in the increase of the peak temperature.


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