Mechanical Properties of Kenaf - Unsaturated Polyester Composites: Effect of Fiber Treatment and Fiber Length

2011 ◽  
Vol 311-313 ◽  
pp. 260-271 ◽  
Author(s):  
E. Osman ◽  
A. Vakhguelt ◽  
I. Sbarski ◽  
S. Mutasher
Keyword(s):  
Modulus Of Elasticity ◽  
Natural Fiber ◽  
Unsaturated Polyester ◽  
Weight Fraction ◽  
Weight Percent ◽  
Natural Fibre ◽  
Kenaf Fiber ◽  
Regular Trend ◽  
Theoretical Predictions ◽  
Naoh Solution

Kenaf fibre is a natural fibre which is growing in popularity due environmental issues and its properties as filler. Unsaturated polyester was used in this investigation via add 1% MEKP concentration ratio as the catalyst. This matrix was combined with untreated kenaf fiber with various fiber sizes (1-6) mm and (10-30) mm, alkalized with 6% NaOH solution for treated kenaf fiber to form natural fiber for two different fiber lengths composites. Composites were prepared by adding various percentages of kenaf fiber in unsaturated polyester resin. A general trend was observed whereby alkalized fiber composites possessed superior flexural strength and modulus and the maximum strength and modulus was at the 20wt% weight fraction. The length of (10-30) mm gave higher tensile and flexural properties compared to (1-6) mm. The modulus of elasticity showed a regular trend of an increase with fiber weight percent until 30% for both fiber lengths and afterwards a decrease in modulus of elasticity for composites with greater fiber weight fraction. The experimental modulus of elasticity was compared with the theoretical predictions and was found to be in good agreement with Hirsch’s model while the results obtained from Cox – Krenchel underestimating the experimental data.

scholarly journals Effects of Irradiation by UV- Acceleration on Mechanical Properties of Polymer Blends (Polyester: Starch)

2018 ◽  
Vol 21 (1) ◽  
pp. 147 ◽  
Author(s):  
Sihama I. Salih ◽  
Qahtan A. Hamad ◽  
Safaa N. Abdul Jabbar ◽  
Najat H. Sabit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Polymer Blends ◽  
Modulus Of Elasticity ◽  
Unsaturated Polyester ◽  
Flexural Modulus ◽  
Weight Ratio ◽  
Weight Fraction ◽  
Elongation Percentage

This work covers mixing of unsaturated polyester (un- polyester) with starch powders as polymer blends and study the effects of irradiation by UV-acceleration on mechanical properties of its. The unsaturated polyester was mixing by starch powders at particle size less than (45 µm) at selected weight fraction of (0, 0.5, 1, 1.5, 2, 2.5 and 3%). These properties involve ultimate tensile strength, modulus of elasticity, elongation percentage, flexural modulus, flexural strength, fracture toughness, impact strength and hardness. The results illustrate decrease in the ultimate tensile strength at and elongation percentage, while increasing modulus of elasticity, with increasing the weight ratio of starch powder to 3 % weight fraction, whereas the maximum value of hardness and flexural, impact properties happened at 1 % weight fraction for types of polymer blends.

Water Resistance and Tensile Strength of High Density Polyethylene (HDPE) Composites

2015 ◽  
Vol 1134 ◽  
pp. 34-38 ◽  
Author(s):  
Nurul Atiqah Mohd Ayob ◽  
Mansur Ahmad ◽  
Nurul Nadia Mohd Khairuddin
Keyword(s):  
Tensile Stress ◽  
Water Absorption ◽  
Modulus Of Elasticity ◽  
Tensile Modulus ◽  
Weight Fraction ◽  
Test Sample ◽  
Natural Fibre ◽  
Thickness Swelling ◽  
Fibre Composites ◽  
Coconut Coir

In this paper, three type of natural-fibre reinforced polyethylene were produced. They are the coconut coir reinforced polyethylene (RPCC), kenaf reinforced polyethylene (RPKC) and bamboo reinforced polyethylene (RPBC). Water absorption test, thickness swelling test and tensile test of the different natural fibre composites were carried-out. The mass of HDPE and natural fibre were based on percentage of filler loading. Each board types were produced with two fibre ratios which are at fourty percent and thirty percent. The preparation of the test sample is according to ASTM D1037 and ASTM D638. The tensile modulus of elasticity, tensile stress, water absorption and thickness swelling of kenaf and bamboo reinforced polyethylene composites were found to increase with increasing fibre weight fraction. Kenaf and bamboo composites showed compatible result for tensile stress and tensile modulus of elasticity while coconut coir appears to be otherwise. However, coconut coir fibre composites displayed comparable results to kenaf and bamboo for both water and thickness swelling. There were significant differences in both tensile properties and the percentage of the water absorption among composites.

scholarly journals Mechanical, Curing Parameters and Water Absorption of Hybrid Date Palm Leaf-Orange Peel Fibers Reinforced Unsaturated Polyester Composites

2021 ◽  
Vol 31 (3) ◽  
pp. 139-144
Author(s):  
Hamza Chelali ◽  
Ahmed Meghezzi ◽  
Abir Berkouk ◽  
Mohamed Toufik Soltani ◽  
George Winning
Keyword(s):  
Tensile Strength ◽  
Date Palm ◽  
Moisture Absorption ◽  
Natural Fiber ◽  
Alkali Treatment ◽  
Unsaturated Polyester ◽  
Natural Fibers ◽  
Orange Peel ◽  
Weight Fraction ◽  
Palm Leaf

In this study, polymer-hybrid natural fibers composites were prepared using unsaturated polyester resin (UPR) as the matrix and a filler using date palm leaf fiber (DPLF) and orange peel fiber (OPF). The effect of DPLF and OPF on mechanical behavior (tensile strength and elongation at break), moisture absorption, UPR gel time (tgel) and peak exothermic temperature (Tpeak) were determined. The composites of UPR reinforced with DPLF and OPF were processed by hand lay-up technique. The UPR weight fraction was maintained at 90%, and DPLF/OPF proportions varied so that the percentage of natural fiber was 10 wt%. Seven (07) composites were prepared (C1, C2, C3, C4, C5, C6 and C7) with different DPLF:OPF ratios (0:0, 1:0, 0.75:0.25, 0.5:0.5, 0.33:0.67, 0.25:0.75, 0:1) respectively in order to screen the possible interactions. DPLF were surface modified using 6% Alkali treatment, OPF were used without surface modification. Unlike DPLF, OPF showed considerable increase of UPR tgel and Tpeak which act as natural inhibitor. Tensile strength and fracture strength were also impacted negatively and positively depending on the different fiber proportions. Absorption tests showed a decrease in the composites hydrophobicity which increases significantly with higher DPLF proportions.

Alkali Treatment of Kenaf Fiber Mat and its Influence on the Performance of Unsaturated Polyester/Kenaf Fiber Mat Composites

2014 ◽  
Vol 1024 ◽  
pp. 171-174 ◽  
Author(s):  
Razaina Mat Taib ◽  
Dody Ariawan ◽  
Zainal Arifin Mohd Ishak
Keyword(s):  
Water Absorption ◽  
Room Temperature ◽  
Alkali Treatment ◽  
Unsaturated Polyester ◽  
Flexural Modulus ◽  
Kenaf Fiber ◽  
Fiber Mats ◽  
Needle Punching ◽  
Naoh Solution ◽  
Treated Fiber

Non-woven kenaf fiber mats were prepared from untreated and alkali treated fibers by using a carding machine followed by needle punching. The alkali treatment was carried out by immersing the fiber mats in 6% NaOH solution for 0, 1, 2, 3, 4, and 5 h at room temperature. The untreated and alkali treated fiber mats were impregnated with unsaturated polyester resin via a resin transfer molding technique to form composites. Maximum improvements of flexural strength and flexural modulus of the composites were observed when the fiber mat was alkali treated for 3 h. The improved of both properties can be attributed to better fiber-matrix adhesion between the alkali treated kenaf fiber and the unsaturated polyester matrix most probably via mechanical interlocking. Water absorption tests were conducted by immersing the composite samples in distilled water at room temperature. The water absorption patterns of all the composites were found to follow Fickian behavior. The tendency of the composites to absorb water decreased when the alkali treated fiber mats were used.

Environmental Degradation Behavior of Kenaf Fiber Mat Composite

2014 ◽  
Author(s):  
Mengyuan Liao ◽  
Toshihiko Hojo ◽  
Guijun Xian ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Weight Change ◽  
Fossil Fuels ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Unsaturated Polyester ◽  
Extreme Temperature ◽  
Performance Ratio ◽  
Monsoon Climate ◽  
Kenaf Fiber

Nowadays “eco-design” is becoming a philosophy to guide next generation of materials and products as global environmental issue produced by fossil fuels and resource overusing. With an industrial increasing interest in sustainable, eco-efficient and green material’s application, natural fiber in polymer composite is guided to develop rapidly. As well know that, natural fibers possess advantages over synthetic or manmade fibers due to its abundance, biodegradability, CO2 neutrality, excellent price/performance ratio and comparable specific strength properties. However, outdoor applications of natural fiber composite are still constrained and raising concerns in terms of their durability, including UV resistance, moisture resistance and extreme temperature withstand and dimensional stability. Continuing with previous research on kenaf non-woven reinforced unsaturated polyester composites three months degradation performance, in order to get a good knowledge of its degradation process/cycle in complicated outdoor environments, longer degradation periods up to 6 months and 12 months in this paper were added for further investigation and comparison. Initially, three sets of kenaf fiber mat composite samples were located in extreme cold temperature (Harbin), mild sea climate Kyoto (Japan), subtropical marine monsoon climate Shanghai (China) and tropical monsoon climate Zaria (Nigeria) respectively from the same starting time until predetermined ageing periods, afterwards weight change and mechanical behavior in terms of tensile, flexural, impact and fracture toughness were measured instrumentally for ageing effect discussion and comparison. As expected, the aged specimens in those different positions all showed the dropped mechanical properties with increasing ageing periods. Furthermore, the trend of degradation in various mechanical parameters was established, which demonstrated weight loss made more serious effect on aged sample’s mechanical properties’ reduction than water absorption behavior. In a word, dropped mechanical properties of the degraded composites accompanied with weight change behavior were clarified, in which degradation phenomenon of embrittled the matrix polymer, deteriorated reinforced fiber and interfacial properties were detected.

scholarly journals A Review on Effect of Orientation Fabric on Mechanical Energy Absorption Natural Fibres Reinforced Composites

2015 ◽  
Vol 773-774 ◽  
pp. 134-138 ◽  
Author(s):  
S.N.A. Khalid ◽  
Al Emran Ismail ◽  
Muhd Hafeez Zainulabidin
Keyword(s):  
Energy Absorption ◽  
Natural Fiber ◽  
Mechanical Energy ◽  
Natural Fibers ◽  
Natural Fibre ◽  
Total Force ◽  
Kenaf Fiber ◽  
Combination Technique ◽  
Absorption Performance ◽  
Angle Orientation

This paper presents the combination technique in developing the woven kenaf fiber that is used as a new method to improve energy absorption performance. This method focuses on the effect energy absorption of angle orientation. Due to the low density, natural fiber such as kenaf fiber provides comparatively good mechanical properties. Thus, natural fibers have high potential for better reinforcement in light weight structures on automotive applications. Total force, total energy, and energy absorption of natural fibre reinforced composite for different type’s natural fibre and angle orientation are discussed and reviewed.

scholarly journals Tensile behaviour for mercerization of single kenaf fiber

2018 ◽  
Vol 14 (4) ◽  
pp. 437-439 ◽  
Author(s):  
Mohamad Ikhwan Ibrahim ◽  
Mohamad Zaki Hassan ◽  
Rozzeta Dolah ◽  
Mohd Zuhri Mohamed Yusoff ◽  
Mohd Sapuan Salit
Keyword(s):  
Natural Fiber ◽  
Polymeric Composite ◽  
Alkaline Treatment ◽  
Manufacturing Industries ◽  
Tensile Behaviour ◽  
Kenaf Fiber ◽  
The Poor ◽  
Naoh Solution ◽  
Kenaf Fibers ◽  
Poor Adhesion

A natural fiber including kenaf fibers that reinforce with polymeric composite has increased attention in the manufacturing industries. However, the poor adhesion between fiber and matrix are commonly encountered respectively to their compatibility nature namely hydrophilic and hydrophobic. Therefore, alkaline treatment has introduced to reduce the hydrophilic effect of natural fiber. This paper presents the treatment of single kenaf fibers following tensile test and predicted using analysis of variance (ANOVA). Here, the kenaf fibers were modified using NaOH at different solutions. Then, the single kenaf fiber was performed under ASTM D3379-89 standard. The results showed that kenaf fiber which treats with NaOH solution of 6% significantly offered the outstanding performance of the tensile behaviour.

scholarly journals Incorporation of Natural Fibres in Rendering Mortars for the Durability of Walls

2021 ◽  
Vol 6 (6) ◽  
pp. 82
Author(s):  
Cinthia Maia Pederneiras ◽  
Rosário Veiga ◽  
Jorge de Brito
Keyword(s):  
Modulus Of Elasticity ◽  
Drying Shrinkage ◽  
High Water ◽  
Natural Fibre ◽  
Accelerated Ageing ◽  
Flax Fibres ◽  
Aesthetic Appearance ◽  
Cement Binder ◽  
Drying Rates ◽  
Adherence Strength

One of the main functions of renders, together with the overall aesthetic appearance of the building, is the protection of the walls against external aggressive actions, such as water, salts solutions, erosion, and mechanical impacts. However, some anomalies of renders may drastically hinder their protection ability. In fact, cracking, high water permeability, and loss of adherence to the substrate of renders limit their barrier effect and favour the exposure of the substrate to external actions. The incorporation of fibres in mortars is commonly pointed out to reduce their cracking susceptibility, due to the probable enhancement in tensile strength and ductility of the composite. The use of lime in substitution of the part of the cement binder is seen as a method to reduce the modulus of elasticity and therefore enhance the resistance to cracking due to drying shrinkage. Therefore, this study investigates the wall protection-related properties of natural fibre-reinforced renders with cement-lime as a binary binder at 1:1:6 volumetric ratio. With this purpose, wool, coir, and flax fibres are used at 20% by total mortar volume and the water behaviour, cracking susceptibility, and adherence to the substrate of the mortars are assessed. Specifically, the water absorption by capillarity, drying rates, permeability to water under pressure, adherence strength, and shrinkage are evaluated. In order to evaluate the renders’ durability and therefore the durability of the protection to the walls, an artificial accelerated ageing test is performed based on heating-freezing and humidification-freezing cycles. The results indicate that the fibres’ addition reduced the shrinkage and modulus of elasticity of the mortars, which suggests lower susceptibility to cracking. The addition of fibres in mortars seemed to slightly affect their water performance and only at early ages. From the results, it was concluded that the adherence strength is not affected by the fibres’ incorporation. The fibres seem also to reduce the impacts of the ageing cycles on the mortar and the improvements provided by the fibres’ addition to the mortars’ performance remained after ageing when compared to the mortars without fibres, thus being a potential alternative to increase their durability. These aspects are particularly important for buildings, since they can extend their service life and promote their sustainability.

scholarly journals Effects of particulates and lipids on the hydraulic conductivity of Matrigel

2008 ◽  
Vol 105 (2) ◽  
pp. 621-628 ◽  
Author(s):  
William J. McCarty ◽  
Melissa F. Chimento ◽  
Christine A. Curcio ◽  
Mark Johnson
Keyword(s):  
Extracellular Matrix ◽  
Hydraulic Conductivity ◽  
Weight Fraction ◽  
Low Density Lipoproteins ◽  
Blood Vessel Wall ◽  
Connective Tissues ◽  
Rigid Particles ◽  
Ldl Particles ◽  
Transmission Electron ◽  
Theoretical Predictions

The hydraulic conductivity of a connective tissue is determined both by the fine ultrastructure of the extracellular matrix and the effects of larger particles in the interstitial space. In this study, we explored this relationship by examining the effects of 30- or 90-nm-diameter latex nanospheres or low-density lipoproteins (LDL) on the hydraulic conductivity of Matrigel, a basement membrane matrix. The hydraulic conductivity of Matrigel with latex nanospheres or LDL particles added at 4.8% weight fraction was measured and compared with the hydraulic conductivity of Matrigel alone. The LDL-derived lipids in the gel were visualized by transmission electron microscopy and were seen to have aggregated into particles up to 500 nm in size. The addition of these materials to the medium markedly decreased its hydraulic conductivity, with the LDL-derived lipids having a much larger effect than did the latex nanospheres. Debye-Brinkman theory was used to predict the effect of addition of particles to the hydraulic conductivity of the medium. The theoretical predictions matched well with the results from adding latex nanospheres to the medium. However, LDL decreased hydraulic conductivity much more than was predicted by the theory. The validation of the theoretical model for rigid particles embedded in extracellular matrix suggests that it could be used to make predictions about the influence of particulates (e.g., collagen, elastin, cells) on the hydraulic conductivity of the fine filamentous matrix (the proteoglycans) in connective tissues. In addition, the larger-than-predicted effects of lipidlike particles on hydraulic conductivity may magnify the pathology associated with lipid accumulation, such as in Bruch's membrane of the retina during macular degeneration and the blood vessel wall in atherosclerosis.

Sign in / Sign up

Export Citation Format

Share Document