scholarly journals The Effect of Alkali Treatment on Physical, Mechanical and Thermal Properties of Kenaf Fiber and Polymer Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2005
Author(s):  
Nur Farhani Ismail ◽  
Nabilah Afiqah Mohd Radzuan ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Che Hassan Che Haron
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Alkali Treatment ◽  
Epoxy Composites ◽  
Effect Of Temperature ◽  
Mechanical And Thermal Properties ◽  
Compression Moulding ◽  
Kenaf Fiber ◽  
Pull Out ◽  
Kenaf Fibers

The use of kenaf fiber as a reinforcement material for polymer composites is gaining popularity, especially in the production of automotive components. The main objective of this current work is to relate the effect of alkali treatment on the single fiber itself and the composite material simultaneously. The effect of temperature condition during mechanical testing is also investigated. Composite materials with discontinuous natural kenaf fibers and epoxy resin were fabricated using a compression moulding process. The epoxy composites were reinforced with 50 wt% untreated and treated kenaf fibers. The kenaf fiber was treated with NaOH solution (6% by weight) for 24 h at room temperature. Kenaf fiber treated with NaOH treatment had a clean surface and no impurities. For the first time we can see that alkali treatment had a damaging effect on the mechanical properties of kenaf fibers itself and the treated kenaf/epoxy composites. The composite reinforced with untreated kenaf fiber and treated kenaf fiber showed increased tensile strength (72.85% and 12.97%, respectively) compared to the neat epoxy. Reinforcement of the composite with treated kenaf fiber decreased the tensile strength due to the fiber pull out and the formation of voids which weakens the adhesion between the fibers and matrix. The temperature conditions also play an important role in composites with a significant impact on the deterioration of composite materials. Treated kenaf fiber has thermal stability and is not sensitive to temperature and as a result reinforcement with treated kenaf gives a lower loss value of 76%.

Mechanical and Thermal Properties of Al2O3-Filled Epoxy Composites

2016 ◽  
Vol 868 ◽  
pp. 111-117
Author(s):  
Xiao Ping Zhang ◽  
Fan Sun ◽  
Bo Wang ◽  
Jian Feng Yang ◽  
Wei Dong Ding ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Epoxy Polymer ◽  
Epoxy Composites ◽  
Mechanical And Thermal Properties ◽  
Pull Out ◽  
Recovery Strain ◽  
Alumina Particles ◽  
Crack Pinning ◽  
Platelet Shape

The paper presents studies of influences of platelet-shape alumina content on the morphology, mechanical and thermal properties of Al2O3/epoxy composites. The alumina particles were pre-treated with surface modifier, and its addition contents were ranged from 17 to 40vol.%. It was found that tensile strength and thermal conductivity increased with the increase of the alumina contents. The fracture surface investigation showed that several strengthening mechanisms, including particles pull-out, crack pinning, plastic void growth and deformation were the main factors for the increments of the tensile strength of the Al2O3/epoxy composites. Comparing with pure epoxy polymer, the creep strain values at 70 °C for 1800 s and recovery strain after 3600 s of 40vol.%Al2O3/epoxy composites was lower as 0.23% and 70%, respectively. It was due to effective prohibition of the slippage and disentanglement of epoxy polymer molecules by the rigid Al2O3.

Micro Palm and Kenaf Fibers Reinforced PLA Composite: Effect of Volume Fraction on Tensile Strength

2011 ◽  
Vol 145 ◽  
pp. 1-5 ◽  
Author(s):  
K.W. Neoh ◽  
Kim Yeow Tshai ◽  
P.S. Khiew ◽  
Chin Hua Chia
Keyword(s):  
Tensile Strength ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Environmental Concern ◽  
Raw Materials ◽  
Kenaf Fiber ◽  
Composite Effect ◽  
Fiber Loading ◽  
Biodegradable Composite ◽  
Kenaf Fibers

Extensive environmental concern associated with the disposal of solid plastic wastes has stirred tremendous interest in the production and use of sustainable biodegradable polymers. Among the vast variety of available materials, Polylactic Acid (PLA) standout as the most commercially viable mass produced resin to date. However, its low thermal and mechanical stability, excessive brittleness, and relatively higher cost have led to numerous research efforts in producing biodegradable polymer composite filled with natural organic fibers. This paper describes the preparation and the mechanical characteristics of a compression molded biodegradable composite made entirely of renewable raw materials. The composites were reinforced with pulverized palm, kenaf and alkali (1M NaOH:fiber in ratio 2:1) treated kenaf fibers, at a fiber mass proportion of 20 to 60% blended PLA and processed in a custom-built compression mold. SEM microscan revealed that the kenaf fiber has a mean diameter of 40μm, length 1236.6μm, and aspect ratio of 31 while the measured values for palm fiber was 58.7μm, 1041.2μm, and 17.7, respectively. All resulting composites showed significant enhancement in tensile strength. At 20, 40 and 60% fiber loading, the palm/PLA composite recorded tensile strength increment of 46.9, 47.8 and 36.6%, respectively. For the kenaf/PLA composite, greatest improvement was achieved at 40% fiber loading with alkali treated kenaf, with approximately 54% higher than the neat PLA while only 12.6% was recorded for the non-treated kenaf/PLA composite, signifying that the surface modification greatly improved fiber-matrix adhesion. SEM observations on the fracture surface showed similar findings. Compared to commercially available palm/Polypropylene (palm/PP) composite at 50% fiber loading, our measured tensile strength for the PLA composite loaded with 40% alkali treated kenaf fiber was still about 20% lower. Further enhancement in the mechanical characteristic of the kenaf/PLA composite is required to push for its wider utilization in the polymer industry.

scholarly journals Influence of layering pattern of modified kenaf fiber on thermomechanical properties of epoxy composites

2019 ◽  
Vol 36 (1) ◽  
pp. 47-62
Author(s):  
AR Mohammed ◽  
MS Nurul Atiqah ◽  
Deepu A Gopakumar ◽  
MR Fazita ◽  
Samsul Rizal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Modification ◽  
Epoxy Matrix ◽  
Epoxy Composites ◽  
Woven Composites ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Kenaf Fibers ◽  
The Impact ◽  
Woven Kenaf

Natural fiber-reinforced composites gained considerable interest in the scientific community due to their eco-friendly nature, cost-effective, and excellent mechanical properties. Here, we reported a chemical modification of kenaf fiber using propionic anhydride to enhance the compatibility with the epoxy matrix. The incorporation of the modified woven and nonwoven kenaf fibers into the epoxy matrix resulted in the improvement of the thermal and mechanical properties of the composite. The thermal stability of the epoxy composites was enhanced from 403°C to 677°C by incorporating modified woven kenaf fibers into the epoxy matrix. The modified and unmodified woven kenaf fiber-reinforced epoxy composites had a tensile strength of 64.11 and 58.82 MPa, respectively. The modified woven composites had highest flexural strength, which was 89.4 MPa, whereas, for unmodified composites, it was 86.8 MPa. The modified woven fiber-reinforced epoxy composites showed the highest value of flexural modulus, which was 6.0 GPa compared to unmodified woven composites (5.51 GPa). The impact strength of the epoxy composites was enhanced to 9.43 kJ m−2 by the incarnation of modified woven kenaf fibers into epoxy matrix. This study will be an effective platform to design the chemical modification strategy on natural fibers for enhancing the compatibility toward the hydrophobic polymer matrices.

The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Polymer Composites ◽  
Epoxy Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.

The Influence of Alkali Treatments on Tensile Strength and Surface Morphology of Cellulose Microfibrils

2015 ◽  
Vol 1123 ◽  
pp. 147-150 ◽  
Author(s):  
Harini Sosiati ◽  
Henny Pratiwi ◽  
Dwi Astuti Wijayanti ◽  
Soekrisno
Keyword(s):  
Tensile Strength ◽  
Surface Morphology ◽  
Room Temperature ◽  
Marked Decrease ◽  
Alkali Treatment ◽  
Fiber Surface ◽  
Cellulose Microfibrils ◽  
Kenaf Fiber ◽  
Fiber Degradation ◽  
Surface Morphologies

Cellulose microfibrils were extracted from kenaf fiber by alkali treatments under various conditions to further characterize their properties and verify the factors which induce fiber degradation. Before treatment, the surface morphologies of the base, middle and tip of the raw fiber were observed. The tensile strength of untreated and treated fibers was measured with a universal tensile machine (UTM). Changes in surface morphologies of cellulose microfibrils were characterized by scanning electron microscopy (SEM). Fourier transform infrared (FTIR) spectroscopy was used to characterize the functional group related to cellulosic and non-cellulosic phases. Surface morphology of the middle of the fiber was denser and stronger than that of the periphery and therefore used to define an initial condition of fiber specimen. Alkali treatment in 6% NaOH at room temperature for 1 h increased the tensile strength of the microfibril; 9% NaOH at 100°C for 2 h results in a marked decrease. Damage to the fiber surface and loss of crystallinity were associated with decreased tensile strength.

Minimizing Property Variation in Natural Fiber Reinforcements for Green Composite Materials Applications

2017 ◽  
Vol 894 ◽  
pp. 50-55
Author(s):  
Leslie Joy L. Diaz ◽  
Stella Marie Hagad ◽  
Peter June M. Santiago
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Natural Fiber ◽  
Large Deviation ◽  
Alkali Treatment ◽  
Unsaturated Polyester ◽  
Natural Fibers ◽  
Critical Length ◽  
Middle Section ◽  
Property Variation

Properties of composite materials are often predicted from properties of its component materials. In the case of green composites that are typically filled with natural fibers however, a large deviation from predictions is observed due to the large property variation in natural fibers. In this study, techniques have been developed to minimize the effect of the said variations, which included the determination of a fiber useful length and critical length, and the utilization of controlled chemical treatment to remove unwanted fiber components that interfere in fiber-matrix interfacial bonding. The abaca fiber was determined to have a diameter of 190 + 2 mm in about two-thirds of the fiber length in the middle section. A large variation in fiber diameter was observed at the root and tip sections such that the diameter could be as high as 200 mm at the root while the tip tapers to 110 to 165 mm. The useful length with constant diameter was determined to be about 2000 mm at the middle section. The critical length of this useful length was found to be 3.15 mm. The tensile strength was also determined to have an average of 970 MPa when measured at 15 mm gauge lengths but is found to decrease up to 796 MPa with increasing gauge lengths up to 35 mm. This superior tensile strength of abaca is also associated to the 2-3o microfibril misorientation from the axis of the fiber. Use of the fibers in composite as continuous and unidirectional filler at 5% loading to unsaturated polyester (tensile strength of 40 MPa) resulted to a tensile strength of 48 MPa. The tensile strength increased to 71 MPa when chemically treated continuous fiber was employed. Alkali treatment at relatively high temperature improved the surface morphology of the fiber, with waxes and lignin removed from the surface and activating the surface with hydroxyl functional groups, that essentially improved the wettability of the polymer to the fiber, and densified the fiber with the closure of its lumens.

scholarly journals Effect of Silicon Carbide on the Mechanical and Thermal Properties of Snake Grass/Sisal Fiber Reinforced Hybrid Epoxy Composites

2021 ◽  
Vol 24 (2) ◽  
pp. 120-128
Author(s):  
M Vijayakumar ◽  
K Kumaresan ◽  
R Gopal ◽  
S D Vetrivel ◽  
V Vijayan
Keyword(s):  
Silicon Carbide ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Epoxy Composites ◽  
Sisal Fiber ◽  
Mechanical And Thermal Properties ◽  
Potential Candidate ◽  
Compression Moulding ◽  
Energy Devices ◽  
Percentage Of Water Absorption

In this study, an attempt was made to develop and characterize Snake Grass Fiber (SGF)/Silicon Carbide (SiC)/epoxy and Snake Grass Fiber/Sisal Fiber (SF)/Silicon Carbide/epoxy hybrid composites using a compression moulding technique. Mechanical characteristics of the produced hybrid composites such as tensile, flexural, and hardness tests were analyzed. Also experiments have been carried out to predict the thermal stability of the fabricated composite samples. The interface between fiber and matrix was examined by using Scanning Electron Microscopy (SEM). Among SGF/SiC/epoxy and SGF/SF/SiC/epoxy composites, it has been observed that hybrid composite SGF/SF/SiC/epoxy exhibits the higher hardness of 82 Shore-D, tensile strength of 51 MPa and flexural strength of 73 MPa. In contrast to the mechanical properties, the percentage of water absorption was lower in the SGF/SiC/epoxy hybrid composite. It is proven from the results that the SGF/SF/SiC/epoxy hybrid composites will enhance the strength of the composites. This composite material is also a potential candidate for the hardware of energy devices including electrochemical energy along with Fuel Cell systems.

Influence of hygrothermal conditioning on the properties of compressed kenaf fiber / epoxy reinforced aluminium laminates

2020 ◽  
Vol 14 (4) ◽  
pp. 7405-7415
Author(s):  
Edynoor Osman ◽  
Mohd Warikh Abd. Rashid ◽  
Mohd Edeerozey Abd Manaf ◽  
Toshihiro Moriga ◽  
Hazlinda Kamarudin
Keyword(s):  
Water Absorption ◽  
Structural Engineering ◽  
Loss Modulus ◽  
Reference Sample ◽  
Industrial Applications ◽  
Mechanical And Thermal Properties ◽  
Saturation State ◽  
Kenaf Fiber ◽  
Pull Out ◽  
Kenaf Fibre

This study has been carried out to evaluate hygrothermal effect onto kenaf fiber reinforced aluminium laminates (KeRALL) and kenaf fibre reinforce composite (KFRC) as compared to reference sample, pristine (without hygrothermal). Samples were fabricated by warm compression method and successfully immersed at 30, 60 and 80°C in water bath for 5 days. As a result, KeRALL at 30°C shows the lowest water absorption rate compared to those immersed at 60 and 80°C. Both KeRALL and KFRC, at temperature 80°C showed the fastest water absorption and the earliest to reach saturation state, followed by temperature of 60°C and 30°C. Mechanical properties which is flexural and impact shows the decremented trends at temperature of 30°C, 60°C and 80°C. At 30 °C, 7 % show a decrement of interlaminar shear stress (ILSS), followed by 66 % at 60°C and 54 % at 80°C. The decrease is associated with fibre pull out, matrix fracture and delamination as the result of the hygrothermal influence as manifested by the fractographic images. From the DMA results, storage modulus as well as loss modulus of KeRALL was decreased with the increased in temperature.  It can be concluded that hygrothermal gives the significant effect on the physical, mechanical and thermal properties of the KeRALL. Therefore, the newly developed KeRALL composite opens a greater commercial potential for kenaf fibre in structural engineering applications. The finding also suggests that KeRALL definitely has high potential as a new sustainable FML composite and can be considered as a promising candidate for future industrial applications.

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