Preparation and Characterization of Alginate/Polyvinyl Alcohol Composite Fibers Containing Copper Ions

2013 ◽  
Vol 652-654 ◽  
pp. 1562-1565 ◽  
Author(s):  
Jing Guo ◽  
Qian He Chen ◽  
Yu Yan Zhang ◽  
Yu Mei Gong ◽  
Hong Zhang
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Copper Ions ◽  
Fiber Surface ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Pseudoplastic Fluid ◽  
Cu Ions

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.

Fabrication and Characterization of Alginate Fibers by Wet-Spinning

2013 ◽  
Vol 796 ◽  
pp. 87-91 ◽  
Author(s):  
Guo Kai Xu ◽  
Lin Liu ◽  
Ju Ming Yao
Keyword(s):  
Sodium Alginate ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Pseudoplastic Fluid ◽  
Elongation At Break ◽  
Alginate Concentration ◽  
Fabrication And Characterization ◽  
Alginate Fibers ◽  
Dope Concentration

Alginate fibers were prepared by extruding a concentrated sodium alginate solution into calcium chloride coagulation bath. The rheological behavior of different concentrations of sodium alginate solutions were investigated to evaluate the spinnability. The effect of dope concentration on the morphologies and mechanical properties of resulting alginate fibers were examined. The results showed that sodium alginate solutions were pseudoplastic fluid and had good spinnability with concentration ranging in 1.5%-3.5%. Moreover, the morphology of obtained fibers became smoother with increasing sodium alginate concentrations. When the sodium alginate concentration was 3.5%, the tensile strength and elongation at break of alginate fibers reach to 13.6±1.2 cN/tex and 8±0.5%, respectively.

scholarly journals Hemocompatible Chitin-Chitosan Composite Fibers

Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 28 ◽  
Author(s):  
Ekaterina N. Maevskaia ◽  
Oksana P. Kirichuk ◽  
Sergei I. Kuznetzov ◽  
Elena N. Dresvyanina ◽  
Vladimir V. Yudin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Clinical Practice ◽  
Optical Density ◽  
Human Blood ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Prolonged Contact ◽  
The Stability ◽  
Chitosan Composite

Composite chitosan fibers filled with chitin nanofibrils (CNF) were obtained by the wet spinning method. The paper discusses the mechanical properties of such type fibers and their hemocompatibility, as well as the possibility of optimizing these properties by adding chitin nanofibrils. It was shown that low CNF concentration (about 0.5%) leads to an increase in fiber tensile strength due to the additional orientation of chitosan macromolecules. At the same time, with an increase in the content of CNF, the stability of the mechanical properties of composite fibers in a humid medium increases. All chitosan fibers, except 0.5% CNF, showed good hemocompatibility, even on prolonged contact with human blood. The addition of chitin nanofibers leads to decrease in hemoglobin molecules sorption due to the decline in optical density at wavelengths of 414 nm and 540 nm. Nevertheless, the hemolysis of fibers was comparable or even lesser that carbon hemosorbent, which is actively used in clinical practice.

Preparation and Characterization of High Latent Heat Thermal Regulating Fiber Made of PVA and Paraffin

2013 ◽  
Vol 8 (2) ◽  
pp. 155892501300800 ◽  
Author(s):  
Weixing Xu ◽  
Yichao Lu ◽  
Bin Wang ◽  
Jianjun Xu ◽  
Guangdou Ye ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Latent Heat ◽  
Wet Spinning ◽  
Structures And Properties ◽  
Spinning Process ◽  
Change Material ◽  
Thermal Stability Of ◽  
Better Than ◽  
High Latent Heat

A convenient method for preparing the thermal regulating fibers with high latent heat has been developed. PVA thermal regulating fibers were prepared via a wet spinning process, with paraffin being the phase change material. The structures and properties of these fibers were investigated by SEM, TGA, DSC and tensile strength tester. With the paraffin content in the fibers increasing from 30wt% to 70wt%, the latent heat of the fibers increases from 42.8J/g to 87.8J/g and the paraffin phase structures change from separation into partial interconnection. PVA matrix can not wrap paraffin effectively when the paraffin content increases up to 50wt%, so the paraffin loss in the spinning process increases. The thermal stability of fibers with low paraffin content is better than that of fibers with high paraffin content. After 100 heat-and-cool cycles, the latent heat of fibers lose a little. The tensile strength of these thermal regulating fibers is good enough for application in wrapping, filling, and nonwovens.

Preparation of R-BABP Polyimide Fibers via Wet Spinning of Polyamide Acid

2020 ◽  
Vol 869 ◽  
pp. 266-272
Author(s):  
Gleb Vaganov ◽  
Andrei Didenko ◽  
Elena Ivan’kova ◽  
Elena Popova ◽  
Vladimir Elokhovskii ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ethylene Glycol ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Structure And Properties ◽  
Polyimide Fibers ◽  
Thermal Imidization ◽  
Morphology And Mechanical Properties

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.

The Properties of Polyimide Fibers Modified by Functionalized Muti-Wall Carbon Nanotubes Based on Friedel-Crafts Acylation

2017 ◽  
Vol 727 ◽  
pp. 490-496 ◽  
Author(s):  
Yu Feng Wang ◽  
Jun Sun ◽  
Li Xing Dai
Keyword(s):  
Heat Treatment ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Composite Fiber ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Polyimide Fibers ◽  
Functionalized Mwcnts ◽  
Thermal Stability Of

Muti-wall carbon nanotubes (MWCNTs) were functionalized by grafting polyimide (PI) on their surface via Friedel-Crafts acylation. The functionalized MWCNTs (f-MWCNTs) showd less damages than unfunctionalized ones. The partially imidized polyamide acid as-spun fibers containing f-MWCNTs were prepared by wet spinning, and the final PI/f-MWCNTs composite fibers were obtained by heat treatment. The tensile strength of the PI based composite fiber containing 1.0 wt% f-MWCNTs was 818.3 MPa and the Young’s modulus was 9.26 GPa, which were about 81% and 88% higher than those of pure PI fiber, respectively. Besides, the thermal stability of PI/f-MWCNTs composite fibers was obviously improved.

Novel alginate, chitosan, and psyllium composite fiber for wound-care applications

2016 ◽  
Vol 47 (1) ◽  
pp. 20-37 ◽  
Author(s):  
Rashid Masood ◽  
Tanveer Hussain ◽  
Mohsen Miraftab ◽  
Azeem Ullah ◽  
Zulfiqar Ali Raza ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Sodium Alginate ◽  
Wound Care ◽  
Antibacterial Properties ◽  
Coagulation Bath ◽  
Composite Fibers ◽  
Absorption Properties ◽  
Swelling Properties ◽  
Liquid Absorption ◽  
Dope Solution

Alginate/psyllium and alginate/chitosan fibers have great potential for wound-care applications. However, alginate/psyllium fibers have poor tensile strength and alginate/chitosan fibers comparatively have low liquid absorption properties. The main aim was to develop a tri-component fiber with comparatively better tensile strength and liquid absorption properties using three different natural polysaccharides. Alginate, chitosan, and psyllium composite fibers were made by using two different coagulation bath compositions. In method A, psyllium-containing sodium alginate dope solution was extruded into a bath containing CaCl2 and subsequently passed through hydrolyzed chitosan bath, whereas in method B: psyllium-containing sodium alginate dope solution was directly extruded into hydrolyzed chitosan and subsequently passed through CaCl2 bath. The produced fibers were rinsed using 25–100% acetone solutions and dried in air. Tensile, antibacterial, swelling, and absorption properties of these fibers were measured. The study showed that homogeneous fibers can be extruded by using both methods. The fibers produced showed good antibacterial, absorption, and swelling properties. Antibacterial activity of the controlled and composite fibers was more or less the same. However, tensile properties of fibers produced by method A and method B were less than the control alginate–chitosan fibers. The composite fibers produced by method A showed better absorption of saline and solution A than control fiber and composite fibers produced by method B. Therefore, method A is recommended for producing the psyllium-containing alginate chitosan fibers for wound-dressing applications. The fibers produced by this method showed comparable tensile and antibacterial properties, superior absorbency, and swelling properties.

scholarly journals Processing and Characterization of a Polypropylene Biocomposite Compounded with Maleated and Acrylated Compatibilizers

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Brent A. Nerenz ◽  
Michael A. Fuqua ◽  
Venkata S. Chevali ◽  
Chad A. Ulven
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Impact Strength ◽  
Impact Energy ◽  
Interfacial Adhesion ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Particulate Reinforcement

Polypropylene (PP) biocomposites containing 20 wt.% sunflower hull as a particulate reinforcement were compounded and tested under tensile, flexural, and impact loadings. The incorporation of the sunflower hull without compatibilizer resulted in diminished tensile strength and impact energy absorption but increased flexural strength and both tensile modulus and flexural modulus when compared to neat PP. Formulations containing three different chemical compatibilizers were tested to determine their effectiveness in improving the interfacial adhesion between the fiber surface and PP chains. Maleic anhydride grafted with PP (MA-g-PP) achieved greater improvements in tensile strength but reduced impact strength in comparison to an acrylic-acid-grafted PP compatibilizer (AA-g-PP). The molecular weight, graft level, and the ability to affect strength, modulus, and absorbed impact energy were also investigated for the compatibilizers. A MA-g-PP having high molecular weight and low graft level was most effective in improving the investigated properties of a sunflower hull-reinforced polypropylene biocomposite.

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 ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Mechanical Strength ◽  
Adipic Acid ◽  
Room Temperature ◽  
Fiber Diameter ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Carboxyl Groups ◽  
High Tensile Strength ◽  
Acetic Acids

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.

Preparation and characterization of a polyvinyl alcohol/polyacrylamide hydrogel vascular graft reinforced with a braided fiber stent

2019 ◽  
Vol 90 (13-14) ◽  
pp. 1537-1548 ◽  
Author(s):  
Mei-yi Xing ◽  
Cheng-long Yu ◽  
Yu-fen Wu ◽  
Lu Wang ◽  
Guo-ping Guan
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Vascular Graft ◽  
Small Diameter ◽  
Dynamic Compliance ◽  
Clinical Applications ◽  
Polyacrylamide Hydrogel ◽  
Mass Ratio ◽  
Overall Performance

A PVA/PAAm (polyvinyl alcohol/polyacrylamide) hydrogel vascular graft reinforced by a braided fiber stent was prepared in the present work, and a series of characterizations were carried out for evaluating the comprehensive performance of the reinforced hydrogel vascular graft (RHVG), including the morphology, the mechanical properties and the biocompatibility. The results show that hydrogel with a mass ratio of 5:8 (PVA:PAAm) is the best candidate for developing an implantation-oriented vascular graft, whose overall performance is the closest to the requirements of clinical applications. The surface of the PVA/PAAm hydrogel is smooth, and the porous structure is uniform and stable. When the longitudinal strain of the RHVG was 50%, the tensile strength reached 905.6 ± 63.1 kPa, much higher than that of a swine common carotid artery (185 kPa). Moreover, the circumferential tensile strength was significantly enhanced by the integration of the stent, and the circumferential compression recovery reached 93.4 ± 6.7%, showing satisfactory structural stability. Furthermore, the suture retention force approached (9.89 ± 0.64 N), higher than that of a canine femoral artery (7.90 ± 0.36 N). More importantly, the radial dynamic compliance reached 3.11 ± 0.09% under testing pressure of 80–120 mmHg, which is 6.9 times that of a commercial expanded polytetrafluoroethylene vascular graft. Lastly, the RHVG has satisfying cytocompatibility and a low hemolysis rate. In summary, the present work may pave the way for developing a novel small-diameter vascular graft for clinical implantation.

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