Fabrication of strong macrofibers from plant fiber bundles

2021 ◽  
pp. 2140005
Author(s):  
Antonio Norio Nakagaito ◽  
Hitoshi Takagi ◽  
Yusuke Katsumoto
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Hydrogen Bonds ◽  
Cellulose Nanofibers ◽  
Fiber Bundles ◽  
Plant Fiber ◽  
Shape Stability ◽  
Cellulosic Fiber ◽  
Original Shape ◽  
Original Plant

The production of long cellulose macrofibers starting from nanofibers is still complex and expensive. This study proposes a method of manufacturing long macrofibers from plant fiber bundles by chemically extracting non-cellulosic substances but preserving the original shape of the fibers. Once the cellulosic fiber bundles are dried, the original cellulose nanofibers are bridged to neighboring nanofibers by the formation of hydrogen bonds, giving shape stability and enhanced mechanical properties. By the process, the tensile strength was increased by about 50% and the modulus doubled from the original plant fiber bundles.

scholarly journals A Robust, Tough and Multifunctional Polyurethane/Tannic Acid Hydrogel Fabricated by Physical-Chemical Dual Crosslinking

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 239 ◽  
Author(s):  
Jie Wen ◽  
Xiaopeng Zhang ◽  
Mingwang Pan ◽  
Jinfeng Yuan ◽  
Zhanyu Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyethylene Glycol ◽  
Hydrogen Bonds ◽  
Tannic Acid ◽  
Hydroxyl Groups ◽  
Self Healing ◽  
Physical Chemical ◽  
Biomedical Field ◽  
Physical Crosslinking

Commonly synthetic polyethylene glycol polyurethane (PEG–PU) hydrogels possess poor mechanical properties, such as robustness and toughness, which limits their load-bearing application. Hence, it remains a challenge to prepare PEG–PU hydrogels with excellent mechanical properties. Herein, a novel double-crosslinked (DC) PEG–PU hydrogel was fabricated by combining chemical with physical crosslinking, where trimethylolpropane (TMP) was used as the first chemical crosslinker and polyphenol compound tannic acid (TA) was introduced into the single crosslinked PU network by simple immersion process. The second physical crosslinking was formed by numerous hydrogen bonds between urethane groups of PU and phenol hydroxyl groups in TA, which can endow PEG–PU hydrogel with good mechanical properties, self-recovery and a self-healing capability. The research results indicated that as little as a 30 mg·mL−1 TA solution enhanced the tensile strength and fracture energy of PEG–PU hydrogel from 0.27 to 2.2 MPa, 2.0 to 9.6 KJ·m−2, respectively. Moreover, the DC PEG–PU hydrogel possessed good adhesiveness to diverse substrates because of TA abundant catechol groups. This work shows a simple and versatile method to prepare a multifunctional DC single network PEG–PU hydrogel with excellent mechanical properties, and is expected to facilitate developments in the biomedical field.

scholarly journals Influence of Thermal Treatment on Mechanical and Morphological Characteristics of Polyamide 11/Cellulose Nanofiber Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Denis Mihaela Panaitescu ◽  
Raluca Augusta Gabor ◽  
Adriana Nicoleta Frone ◽  
Eugeniu Vasile
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Treatment ◽  
Cellulose Nanofibers ◽  
Morphological Characteristics ◽  
Nanocomposite Films ◽  
Polyamide 11 ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
The Impact

Nanocomposite films were prepared from polyamide 11 (PA11) and cellulose nanofibers (CN) by melt compounding and compression molding. The impact of thermal treatment on the morphology and mechanical behavior of PA11 and nanocomposite films was studied using dynamic mechanical analysis, tensile tests, X-ray diffraction (XRD), and peak force (PF) QNM technique. Slightly higher storage modulus values were obtained for nanocomposites compared to the matrix before the treatment, but a noticeable increase was observed after the treatment. Although CN addition determined increased tensile strength and modulus both before and after the treatment, the increase was much more significant in the case of treated films. The best mechanical properties were shown by treated PA11 films containing 5 wt% CN, with 40% higher Young’s modulus and with 35% higher tensile strength compared to the matrix. Some of the changes pointed out by static and dynamic mechanical tests were explained by the morphological changes determined by the thermal treatment and emphasized by PF QNM and by the increase of XRD crystallinity. A transition from lamellar stack morphology to one involving spherulites was highlighted by AFM. Thermal treatment has proved a valuable method for improving the mechanical properties of PA11/CN composites.

Mechanical Properties of Graphene Oxide/Polyvinyl Alcohol Composite Film

2017 ◽  
Vol 25 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Tao Cheng-an ◽  
Zhang Hao ◽  
Wang Fang ◽  
Zhu Hui ◽  
Zou Xiaorong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Hydrogen Bonds ◽  
Polyvinyl Alcohol ◽  
Composite Film ◽  
Functional Groups ◽  
Failure Strain ◽  
Oh Groups ◽  
Enhancement Mechanism

Graphene oxide (GO) was served as mechanical strengthening to prepare GO/Polyvinyl Alcohol(PVA) composite film. This was accomplished in order to explore the influence of contents of GO on the tensile strength and failure strain of GO/PVA composite film. The results showed that as the GO content increased, the tensile strength of the composite film became greater rapidly at first, and then decreased gradually. When the GO content was 20%, the film had its maximum tensile strength (59.6 MPa). This is over 500% of the tensile strength of pure PVA film. The failure strain of GO/PVA composite film decreased rapidly as the GO content increased. The enhancement mechanism of the composite can be explained by the existence of multi-hydrogen bonds between the hydroxyl (-OH) groups of PVA and oxygen-containing functional groups of GO.

scholarly journals Research on the Strengthening Advantages on Using Cellulose Nanofibers as Polyvinyl Alcohol Reinforcement

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 974 ◽  
Author(s):  
Quim Tarrés ◽  
Helena Oliver-Ortega ◽  
Manel Alcalà ◽  
F. Xavier Espinach ◽  
Pere Mutjé ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
High Performance ◽  
Cellulose Nanofibers ◽  
Cellulosic Fibers ◽  
Reinforcement Content ◽  
Superior Mechanical Properties ◽  
Coupling Factors ◽  
Internal Mixer

The present work aims to combine the unique properties of cellulose nanofibers (CNF) with polyvinyl alcohol (PVA) to obtain high-performance nanocomposites. CNF were obtained by means of TEMPO-mediated ((2,2,6,6-Tetramethylpiperidin-1-yl)oxyl) oxidation, incorporated into the PVA matrix by means of compounding in a single-screw co-rotating internal mixer and then processed by means of injection molding. It was found that CNF were able to improve the tensile strength of PVA in 85% when 4.50 wt % of CNF were added. In addition, the incorporation of a 2.25 wt % of CNF enhanced the tensile strength to the same level that when 40 wt % of microsized fibers (stone groundwood pulp, SGW) were incorporated, which indicated that CNF possessed significantly higher intrinsic mechanical properties than microsized fibers. SGW was selected as reference for microsized fibers due to their extended use in wood plastic composites. Finally, a micromechanical analysis was performed, obtaining coupling factors near to 0.2, indicating good interphase between CNF and PVA. Overall, it was found that the use of CNF is clearly advantageous to the use of common cellulosic fibers if superior mechanical properties are desired, but there are still some limitations that are related to processing that restrict the reinforcement content at low contents.

Fabrication and mechanical properties of flaxseed fiber bundle-reinforced polybutylene succinate composites

2019 ◽  
Vol 50 (1) ◽  
pp. 98-113 ◽  
Author(s):  
Sayed Waqar Azhar ◽  
Fujun Xu ◽  
Yinnan Zhang ◽  
Yiping Qiu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fiber Bundle ◽  
Industrial Applications ◽  
Fiber Bundles ◽  
Sem Images ◽  
Thermal Compression ◽  
Oil Derivatives ◽  
Polybutylene Succinate ◽  
Absolute Potential

Flaxseed plants are widely grown globally due to the beneficial seed oil derivatives for human and animal consumption and other industrial uses. However, plentiful flaxseed straws are annually burnt after the harvesting of seeds, lacking utilization of the abundant flaxseed fibers, resulting in wastage of a valuable fiber resource and drastic increase in environmental pollution. In this study, initially the chemical composition and mechanical property of flaxseed fiber bundle were investigated, which resulted as 40.11% cellulose, 28.27% hemi-cellulose, 15.08% lignin, 6.3% pectin, 3.1% wax, and the tensile strength of 1.14 cN/dTex. The surface modification treatment was carried out with concentrations of 10 g/L and 20 g/L sodium hydroxide (NaOH). Later, flaxseed fiber bundles reinforced Polybutylene Succinate (PBS) resin composites were fabricated by thermal compression method. The tensile strength of untreated flaxseed fiber bundle/PBS composites was 78.2 MPa, while the flexural strength of 20 g/L NaOH treated flaxseed fiber bundle/PBS composites showed 84% increment from 26.70 MPa to 49.16 MPa. The scanning electron microscopy (SEM) images revealed significantly rougher surface morphology and stronger interfacial bonding of the alkali treated fiber bundles with matrix. The good mechanical properties observed demonstrated the absolute potential of resultant composites reinforced by flaxseed fiber bundles for utilization in the civil and industrial applications.

scholarly journals Fabrication of Paper Sheets Coatings Based on Chitosan/Bacterial Nanocellulose/ZnO with Enhanced Antibacterial and Mechanical Properties

2021 ◽  
Vol 22 (14) ◽  
pp. 7383
Author(s):  
Joanna Jabłońska ◽  
Magdalena Onyszko ◽  
Maciej Konopacki ◽  
Adrian Augustyniak ◽  
Rafał Rakoczy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Food Packaging ◽  
Cellulose Nanofibers ◽  
Mechanical Activity ◽  
Bacterial Nanocellulose ◽  
E Coli ◽  
Tearing Resistance ◽  
Shape And Size

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

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