Study on Water Absorption and Impact Properties of Vegetal Composites Material: Composite Structures

2012 ◽  
Vol 530 ◽  
pp. 34-39
Author(s):  
Abdalla Abdal-Hay ◽  
Do Yeon Jung ◽  
Kang Il Lee ◽  
G.T. Abdel-Jaber ◽  
Jae Kyoo Lim

The delamination and fibers pull out have been the main factors failure application of natural fibers in various engineering fields. To address these problems, particles reinforced composites are the promising candidate. The present paper investigates on vegetal particles (date palm seed particles/DPSp) and applies it as composites material reinforced unsaturated polyester (USP). The influence of alkali treatment on the surface morphology and structure of DPSp was investigated. They investigated by SEM and Energy Dispersive Spectroscopy (EDS) mapping. The water absorption results showed directly proportion with the particles loading as the relative increases were 0.645% and 7.345% for 10 wt% and 40 wt% of DPSp content, respectively. In addition, the water absorption ability of the composites showed low value comparing with many natural fibers. In addition, the fracture toughness of the composites was studied. Overall, addition of the proposed DPSp particles may be opens a new avenue to exploit the utilized natural cheap material to produce a green composite.

2021 ◽  
Vol 31 (3) ◽  
pp. 139-144
Author(s):  
Hamza Chelali ◽  
Ahmed Meghezzi ◽  
Abir Berkouk ◽  
Mohamed Toufik Soltani ◽  
George Winning

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.


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.


2018 ◽  
Vol 773 ◽  
pp. 94-99 ◽  
Author(s):  
Venitalitya Augustia ◽  
Achmad Chafidz ◽  
Lucky Setyaningsih ◽  
Muhammad Rizal ◽  
Mujtahid Kaavessina ◽  
...  

The trend of using natural fibers as green filler in the fabrication of polymer composites is increasing. One of these natural fibers is date palm fiber (DPF). Date palm fiber is considered as agricultural waste in certain areas, such as Middle East countries. Therefore, the utilization of this fiber in the composites fabrication is an interesting topic of research. In the current study, composites were prepared by melt blending DPF with high density polyethylene (HDPE). Five different DPF loadings were studied (i.e. 0, 5, 10, 20, 30 wt%). The effect of the DPF loadings on the mechanical properties and water absorption behavior of the composites were investigated. The tensile test result showed that tensile strengths of all the composites samples were all higher than the neat HDPE with the maximum improvement was achieved at the DPF loading of 5 wt% (i.e. DFC-5), which was about 19.23 MPa (138% higher than the neat HDPE). Whereas, the flexural test result showed that the flexural strength of the composites slightly increased compared to that of the neat HDPE only until 5 wt% DPF loading (i.e. DFC-5). Afterward, the flexural strength of the DFC-10 was equal to that of the neat HDPE, and decreasing with further increase of DPF loadings. Additionally, the water absorption test result showed that the water absorption rate and uptake of water (at equilibrium) increased with the increase of DPF loading.


2020 ◽  
Vol 845 ◽  
pp. 3-8
Author(s):  
Khalid Alzebdeh ◽  
Mahmoud Nassar ◽  
Nasr Al-Hinai ◽  
Ramanathan Arunachalam ◽  
Hani Al-Rawahi

Utilization of natural fibers in a form of filler materials in composite structures has been successfully implemented in a broad range of industrial applications. In general, natural fibers have many advantages over synthetic counterparts, (e.g. glass and carbon) including lower density, ability to muffling vibration as well as its positive environmental impact. Hence, natural fibers can be used to enhance the characteristics of composite polymers. Expected improvements may include good thermal and acoustic insulating properties and better electrical resistance. However, in order to qualify any new developed material for commercialization, machining such as drilling, milling, cutting, bending, etc., becomes essential. In this experimental work, a newly developed Chopped Date Palm Fronds Polypropylene (CDPF/PP) bio-composite, which was mechanically characterized in a previous study, is investigated against conventional drilling operation. The data obtained through machining are processed and statistically analyzed based on Design of Experiment (DoE) to achieve the optimal input parameters using ANOVA and regression model. Moreover, the statistical evaluation of the results is useful to develop mathematical models that can be used with confidence to predict the drilling delamination for future works. In specific, optical microscopy was utilized to measure the dimension of the machined bio-composite surface to calculate the delamination factor.


2017 ◽  
Vol 894 ◽  
pp. 50-55
Author(s):  
Leslie Joy L. Diaz ◽  
Stella Marie Hagad ◽  
Peter June M. Santiago

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.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 597 ◽  
Author(s):  
Mohammed Sh. Al-Otaibi ◽  
Othman Y. Alothman ◽  
Maher M. Alrashed ◽  
Arfat Anis ◽  
Jesuarockiam Naveen ◽  
...  

In this study, the effect of different polypropylene (PP) matrices (homopolymer (HPP), impact copolymer (ICP), and recycled polypropylene (rPP)) on the mechanical, morphological, and thermal properties of date palm fiber (DPF)-reinforced PP composites was investigated. The DPFs were treated with an alkali solution, and composites were fabricated with different DPF loadings (5, 10, and 15 wt %) and lengths (less than 2 mm and 8–12 mm). It was found that the tensile properties of the DPF/ICP and DPF/rPP composites were similar to those of the DPF/HPP composites. The addition of fiber to the matrix reduced its tensile strength but increased the modulus. The alkali treatment improved the compatibility between the fibers and the matrix by removing hemicellulose and other impurities. Fourier transform infrared spectroscopy confirmed hemicellulose removal. The morphology of the alkali-treated fractured tensile specimen revealed improved adhesion and less fiber pull out. Differential scanning calorimetry revealed that the alkali treatment enhanced the crystallinity index. Thermogravimetric analysis showed that the addition of DPFs into the PP matrix reduced the thermal stability of the composite. However, the thermal stability of the treated fiber-reinforced rPP and ICP composites was similar to that of the DPF/HPP composite. Hence, rPP can be used as an alternative to HPP with DPFs.


2014 ◽  
Vol 1024 ◽  
pp. 171-174 ◽  
Author(s):  
Razaina Mat Taib ◽  
Dody Ariawan ◽  
Zainal Arifin Mohd Ishak

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.


2017 ◽  
Vol 882 ◽  
pp. 89-100 ◽  
Author(s):  
Omid Nabinejad ◽  
Sujan Debnath ◽  
Teh J. Ying ◽  
Willey Y.H. Liew ◽  
Ian J. Davies

The effect of alkali treatment and nanoclay addition on the mechanical properties and water absorption behavior of rice husk particle (RHP) reinforced unsaturated polyester (UP) composites was investigated. Thermogravimetric analysis (TGA) indicated that the alkali treatment removed most of the hemicellulose and impurities from the RHP with the tensile strength, tensile modulus, flexural strength and flexural modulus of the resulting composites being improved by alkali treatment. The results indicated that the 5% sodium hydroxide concentration had the optimum performance on mechanical strength and water absorption resistance. Furthermore, the influence of nanoclay addition (1, 3 and 5 wt%) on the properties of optimum alkali treated RHP-UP composites was investigated with the lowest content (1 wt%) of nanoclay showing the highest mechanical performance. However, further addition of nanoclay improved the moisture absorption resistance of the composites. Good interface bonding between the filler and matrix was observed from scanning electron micrographs for the optimum RHP alkali treated and nanoclay dispersed RHP-UP composites.


Author(s):  
EKHLAS A. OSMAN ◽  
ANATOLI VAKHGUELT ◽  
IGOR SBARSKI ◽  
SAAD A. MUTASHER

Effects of water absorption on the flexural properties of kenaf-unsaturated polyester composites and kenaf/recycled jute-unsaturated polyester composites were investigated. In the hybrid composites, the total fiber content was fixed to 20 wt%. In this 20 wt%, the addition of jute fiber varied from 0 to 75%, with increment of 25%. The result demonstrates the water absorption and the thickness swelling increased with increase in immersion time. Effects of water absorption on flexural properties of kenaf fiber composites can be reduced significantly with incorporation of recycled jute in composites formulation. The process of absorption of water was found to approach Fickian diffusion behavior for both kenaf composites and hybrid composites.


2012 ◽  
Vol 15 (3) ◽  
pp. 5-14
Author(s):  
Thanh Duy Tran ◽  
Tai Tan Dang

Composite materials are usually made with organic matrixes reinforced by synthetic fillers, such as carbon or glass fibers.... But the high cost and environmental awareness of the synthetic fibers has limited their application. Meanwhile, natural fibers have been very attractive because they have been low cost, low density, eco-friendly, available in high quantities, renewable, biodegradable and shown excellent mechanical properties. In this study, green composite materials were prepared by using unsaturated polyester resins and bamboo fibers. The fibers were previously modified by chemical treatment and inserted into matrix in the role of the reinforcement. Some factors effecting to properties of products showed more advantages than modifier content were studied meticulously. As a result, composite products showed more advantages than neat polymer. For example, it does not only improve significantly mechanical properties but also becomes cheaper and friendlier with environment.


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