Effect of heat treatment on the mechanical properties of jute yarns

2021 ◽  
pp. 002199832199910
Author(s):  
Y Ben Smail ◽  
A El Moumen ◽  
A Imad ◽  
F Lmai ◽  
M Ezahri

In the last two decades, an increasing interest has been observed for the use of natural fibers such as jute fibers in different applications. These fibers are characterized by their low cost and their availability. They are mainly used in fabric bag manufacturing. The objective of this paper is to study the effect of temperature on the mechanical properties of jute yarns. An experimental study was conducted at different temperatures (22 °C; 80 °C; 105 °C and 150 °C) for 24 h. Each degree was followed by tensile testing of the specimen. Besides, the thermo-gravimetric analysis (TGA) was used to investigate the effect of the temperature on the thermal stability and the thermal degradation of the jute fibers. In addition, the statistical analysis was performed using the method of two and three-parameter Weibull distribution to determine the spatial distribution of the properties. The results showed that there was a degradation of the mechanical properties of the jute yarns heated to high temperature compared to the raw yarns (considered as a specimen exposed to 22 °C). The tensile strain and the Young modulus failed by 36% and 13% respectively for the specimens heated at 150 °C and the failure kinematic of the jute fiber was affected by the temperature of heating. The TGA showed that the thermal stability of the jute yarns was affected by two factors: fibers drying and their changing temperatures.

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
K. Manohar Reddy ◽  
D. Harsha Vardhan ◽  
Y. Santhosh Kumar Reddy ◽  
Gujjala Raghavendra ◽  
Ramesh Rudrapati

The advancement of composites mixed with natural fibers and with fillers has become the most supportable alternative material for engineering applications, especially in industries such as automotive and aerospace. Natural fibers are renewable, cheap, biodegradable, and ecological materials. In the present work, already used woven jute fibers, which are extracted from gunny bags with the same grams per square meter (GSM), were used, and then, woven jute fibers were chemically treated to improve their characteristics. Graphite powder-filled used jute fiber reinforced epoxy composite (UJF) are prepared by using the hand-layup technique. Tests such as tensile, flexure, impact, and thermo-gravimetric analysis (TGA) were conducted. These tests were according to ASTM standards to evaluate the effect of graphite filler content on hybrid epoxy jute composites. The composite material is prepared by changing the content by weight of the filler by 3%, 6%, 9%, and 12%. The experimental results reveal that 6% of the graphite composites showed the maximum tensile strength and modulus. With the increase in the filler content, there is a decrease in the flexural properties. The impact resistance increases slightly up to 6% of the filler content. The study of thermal decomposition showed that the lowest mass loss was found at 9% by weight of the filler content. Morphological analysis performed by FE-SEM showed that the addition of filler content improved the binding of the fiber and matrix up to 6% by weight of the filler content. It should be noted that these hybrid composites are a promising material at low cost for lightweight structural applications.


2011 ◽  
Vol 415-417 ◽  
pp. 666-670 ◽  
Author(s):  
Na Lu ◽  
Shubhashini Oza ◽  
Ian Ferguson

Natural fiber reinforced composites are being used as reinforcement material in composite system due to their positive environmental benefits. Added to that, natural fibers offer advantages such as low density, low cost, good toughness, high specific strength, relatively non-abrasive and wide availability. However, the low thermal stability of natural fibers is one of the major challenges to increase their use as reinforcing component. In this study, a thorough investigation has been done to compare the effect of two chemical treatment methods on the thermal stability of hemp fibers. 5wt% sodium hydroxide and 5wt% triethoxyvinylsilane was used for the treatment of hemp fibers. Fourier transform infrared spectroscopy, scanning electron microscopy and thermo gravimetric analysis were used for characterization of untreated and treated fiber. The results indicated that 24 hours alkali treatment and 3 hours silane treatment time enhanced the thermal stability of the hemp fiber. However, alkali treatment shows better improvement compared to silane treatment.


2015 ◽  
Vol 1087 ◽  
pp. 30-34 ◽  
Author(s):  
KANAGESWARY SOCKALINGAM ◽  
Mohd Azha Yahya ◽  
Hasan Zuhudi Abdullah

Hydroxyapatite (HAp), classified as bioceramic materials is the major mineral constituent of vertebrate bones and teeth. In this study, the effect of temperature on isolation and characterization of HAp from tilapia fish scales have been investigated. Scales were subjected to heat treatment at different temperatures (800°C and 1000°C) and microstructure of both raw and calcined scales were observed under Scanning Electron Microscopy (SEM). Thermo Gravimetric Analysis (TGA) and Energy Dispersive X-Ray Spectroscopy (EDX) results have revealed the best calcination temperature of tilapia scales to be 800°C due to the calculated calcium to phosphorous weight ratio (Ca/P). The Ca/P ratio for scales treated at 800°C and 1000°C were 1.598 and 1.939 respectively. The phase purity and crystallinity of produced HAp was further confirmed by X-Ray Diffraction (XRD) analysis. Based on the study, it can be concluded that tilapia fish scale is a good natural source of HAp with 800°C as the optimum calcination temperature in HAp production.


2014 ◽  
Vol 6 (2) ◽  
pp. 1122-1134 ◽  
Author(s):  
Mokhtar Hemdan Abd El-Salam

Due to the light weight, high specific strength and non hazardous nature of bamboo fiber, it is preferred over synthetic fibers in composite materials for a wide range of applications such as automotive industry and including household sectors. As was noticed, little attention has been given to the effect of bamboo powder on the mechanical properties of rubber composites. Hence, an attempt has been made in this paper to the study the effect of loading and particle size of bamboo powder on the mechanical properties of EPDM composites. Thermo-gravimetric analysis (TGA) was carried out to study the thermal stability of composites. Results indicated that the thermal stability of EPDM was further improved with increasing in bamboo loading and decreasing in particle size. The stress- strain curves of the composites were studied and fitted according toOgden’s model. Mechanical parameters for the studied composites were improved with increasing bamboo loading. Besides, properties such as rupture stress, and internal friction were found to be maximum for composites containing certain content of bamboo powder, depending upon its particle size. Moreover, composites containing the smallest particle size of powder, at all levels of bamboo loading, showed mechanical properties superior to all other composites. From the dynamic mechanical measurements, the dynamic modulus, internal friction, and thermal diffusivity were calculated. The observed variations were explained in view of the role played by both the loading level and the particle size of bamboo powder. These findings were supported by scanning electron microscopy (SEM) micrographs.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hongfei Shang ◽  
Jian Li ◽  
Tianmin Shao

TiN/Ta multilayer film with a modulation period of 5.6 nm and modulation ratio of 1 : 1 was produced by ion beam assisted deposition. Microstructure of the as-deposited TiN/Ta multilayer film was observed by transmission electron microscopy and mechanical properties were investigated. Residual stress in the TiN/Ta multilayer film was about 72% of that of a TiN monolayer film with equivalent thickness deposited under the same conditions. Partial residual stress was released in the Ta sublayers during deposition, which led to the decrease of the residual stress of the TiN/Ta multilayer film. Nanohardness (H) of the TiN/Ta multilayer film was 24 GPa, 14% higher than that of the TiN monolayer film. It is suggested that the increase of the nanohardness is due to the introduction of the Ta layers which restrained the growth of TiN crystal and led to the decrease of the grain size. A significant increase (3.5 times) of theH3/E2(Eelastic modulus) value indicated that the TiN/Ta multilayer film has higher elasticity than the TiN monolayer film. TheLc(critical load in nano-scratch test) value of the TiN monolayer film was 45 mN, which was far lower than that of the TiN/Ta multilayer film (around 75 mN). Results of the indentation test showed a higher fracture toughness of the TiN/Ta multilayer film than that of the TiN monolayer film. Results of differential scanning calorimetric (DSC) and thermo gravimetric analysis (TGA) indicate that the TiN/Ta multilayer film has better thermal stability than the TiN monolayer film.


2010 ◽  
Vol 139-141 ◽  
pp. 129-132
Author(s):  
Dong Fang Li ◽  
Li Li ◽  
Jian Zhang Li

Wood plastic composite (WPC) is very useful new material in the modern society. Improving the interfacial bond strength between wood and plastic is the foundation of improving the properties of WPC. Ethylene vinyl acetate (EVA) was used as the coupling agent of WPC in this study. Thermo-gravimetric analysis (TGA) was employed to study the thermal stability of wood flour modified by EVA. The modulus of rupture (MOR), the modulus of elasticity (MOE), and the tensile strength of WPC were investigated to understand the effects of the vinyl acetate (VA) content and the melt index of EVA on WPC. The results show that EVA could improve the thermal stability of wood flour and the mechanical properties of WPC. The mechanical properties of WPC are increasing with VA content raise and melt index reducing.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2158
Author(s):  
Nanci Vanesa Ehman ◽  
Diana Ita-Nagy ◽  
Fernando Esteban Felissia ◽  
María Evangelina Vallejos ◽  
Isabel Quispe ◽  
...  

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.


2020 ◽  
Vol 115 (4) ◽  
pp. 132-139
Author(s):  
Muhammad Naveed Ashraf ◽  
Shahzad Maqsood Khan ◽  
Shahid Munir ◽  
Rashid Saleem

Formaldehyde has many applications in the chemical industry including synthesis of amino resins which are used in leather processing. After application in leather, these resins are hydrolyzed under certain conditions to release free formaldehyde which has high environmental concerns due to its proven carcinogenic effects. The objective of this work is to develop a formaldehyde free melamine-based resin to produce green leather with improved retanning properties and thermal stability. The optimum melamine resin was synthesized by condensing melamine with glyoxal instead of formaldehyde. Further, the water solubility and improved thermal stability of synthesized melamine resins were achieved by introduction of sulfanilic acid in resin structure. Synthesized resin was used in leather retanning in comparison with commercially available melamine resin as a control. Both leathers were tested for mechanical properties, organoleptic properties, grain surface and fiber structure analysis. Comparative free formaldehyde content was measured in resultant leathers. Effluents of retanning baths were comparatively analyzed. Optimum resin was also characterized by thermo gravimetric analysis and FTIR. The results of this study showed that the experimental resin has imparted significant improvement in mechanical and organoleptic properties of leather as compared to the control resin. Analysis of free formaldehyde content confirmed the absence of free formaldehyde in leather treated with optimum resin while 141 mg/kg formaldehyde was detected in leather treated with control resin. Free formaldehyde was also absent in effluent of experimental resin while 305 mg/kg formaldehyde was detected in effluent of control resin. Moreover, percentage efficiency in COD, TDS and TSS load of effluent was observed as 9.62, 7.2 and 6.31 respectively.  Resultant leather was free from formaldehyde making it safe for human along with reduction in pollution load of tannery.  


Author(s):  
Ênio Henrique Pires da Silva ◽  
Emiliano Barretto Almendro ◽  
Amanda Albertin Xavier da Silva ◽  
Guilherme Waldow ◽  
Flaminio CP Sales ◽  
...  

Composites using natural fibers as reinforcement and biodegradable polymers as matrix are considered environmentally friendly materials. This paper seeks the mechanical and morphological characterization of a biocomposite of polyurethane (PU) derived from a blend of vegetable oils doped with aluminatrihydrate (ATH) and reinforced with hydrated cotton fiber fabric (HCF). The comparison and study were performed based on the properties of the: (i) pure PU; (ii) PU doped with ATH containing 30% of the final mass (PU+30%ATH); (iii) composite of PU reinforced with 7 layers of cotton fiber fabric (PU+7CF); (iv) composite of PU+30%ATH reinforced with 7 layers of CF (PU+30%ATH+7CF); (v) composite of PU+30%ATH reinforced with 7 layers of hydrated cotton fiber fabric (PU+30%ATH+7HCF). The mechanical properties obtained according to the tensile test for the composite PU+30%ATH+CF with fibers oriented at 0° showed a significant increment in tensile strength (60 MPa) and the modulus of elasticity (4.7 GPa) when compared to pure PU (40 MPa) and (1.7 GPa) respectively. PU+30%ATH also presented a rising tensile strength (31 MPa) and Young modulus (2.6 GPa). For the composite with addition of water, results presented a significant decrease in strength (31.3 MPa) and stiffness (0.9 GPa) than the composite with no water. Electron microscopy (SEM) analyses exhibited that the samples with addition of water showed the presence of large amounts of pores and the lower interaction between matrix and fiber. These results may explain the lower mechanical properties of this material. DOI: http://dx.doi.org/10.30609/JETI.2019-7576


2018 ◽  
Vol 16 (36) ◽  
pp. 153-171
Author(s):  
Nahida J. H.

The present work studies the mechanical properties of SiO2 μPs, and NPs in St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends at different concentrations (30, 40, 50, and 60 %). DSC and TGA tests were carried out to the samples evolved. The result showed a single glass transition temperature (Tg) for all St /PVA blends that was attributed to the good miscibility of the blends involved. It was found that (Tg) decrease with starch ratio increase. It was seen that (PVA) of (Tg=105 oC); The glass transition temperature which was decrease with starch ratio that was attributed to glass transition relaxation process due to micro-Brownian motion of the main chain back bond. The endothermic peak at 200 oC was attributed to melting point of (PVA). Thermal properties of PVA; and St /PVA blends at different concentration (30, 40, 50, and 60 %) were evaluated by thermo gravimetric analysis (TGA). The analyses were carried out from 20 to 600 oC at 10 oC)/min heating rate in air oxygen atmosphere. The weight loss stages depended on polymer system. The starch addition causing shifting in the second degradation temperature to the higher temperature; which result in overlapping between the two main degradation steps, these result was attributed to the St/ PVA blend compatibility. The mechanical properties results showed a decrease in ultimate strength with starch ratio increase. The ultimate strength of (PVA) was (47 MPa), whereas the ultimate strength of 60 %St/PVA was (11 MPa) and for 30 %St/PVA was the highest ultimate strength of blends involved (26 MPa). SiO2μPs (753.7 nm), and NPs (263.1 nm) were added at different concentrations (1.5, 2, and 2.5 %). 1.5% SiO2μPs, and NPs of the best ultimate strength (69 MPa), (86 MPa) respectively then it was decreased by SiO2μPs, and NPs increase. Optical microscope of the samples involved was investigated. It was concluded the prepared samples were suggested to be used as packaging materials for agriculture application and its ultimate strength could be controlled by SiO2μPs, and NPs addition.


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