scholarly journals Studies on Water Sorption Behaviour of Laminated Bamboo Polymer Composite

2019 ◽  
Vol 130 ◽  
pp. 01040 ◽  
Author(s):  
Yuniar Ratna Pratiwi ◽  
Indah Widiastuti ◽  
Budi Harjanto

The aim of this article is to evaluate water absorption in bamboo fiber composites. Bamboo is hydrophilic, means that it easily absorbs water. In this study the bamboo fiber-based composites were developed using hand lay up method, with epoxy resin as the matrix constituent. Water absorption characteristics of specimens of bamboo composite and epoxy were determined from water immersion tests at several temperatures. Gravimetric analysis was performed to determine the moisure absorbed as a function of time at two different temperatures: 25 ºC and 50 C. The diffusivity of water in an epoxy bamboo composite was determined after reaching saturation point. During room temperature soaking, epoxy specimen showed the characteristic of Fickian behavior. Similar immersion tests on bamboo-epoxy composites followed nonfickian behavior. Changes in the mechanical properties of material due to water absorption were evaluated from tensile testing on materials with varied water content. It was found that the waterabsorption in all samples reduced the tensile properties. The degradation of tensile properties was greater with an increasing temperature of immersion. The results of this study emphasize the importance ofconsidering deterioration of mechanical properties in the bamboo epoxy composites during their application in water and possibly in humid environment.

2020 ◽  
Vol 10 (1) ◽  
pp. 814-819
Author(s):  
Indah Widiastuti ◽  
Yuniar Ratna Pratiwi ◽  
Dwi Noor Cahyo

AbstractBamboo laminate composites could be the alternative materials in outdoor application. However, the life time prediction of this composite in humid environment became a concern considering hydrophilic property of the bamboo fibre. This research aimed to assess the changes of mechanical properties in the composite with the sorption of water. It employed hand lay-up method in developing the laminate composites with epoxy as the matrix and woven bamboo as the reinforced material. Water sorption characteristic was evaluated through a gravimetric analysis for different water immersion temperatures. The sorption on water was studied by four weeks immersion in room temperature as well as in elevated temperatures of 50∘ and 80∘C. Tensile test was performed to evaluate the mechanical properties of the composite. This research clearly showed the significant effect of bamboo fibre on the strength and water sorption behaviour of the composites. It was observed that the rate of water absorption depends on temperature of immersion. Larger debonding between the bamboo fibre and the epoxy matrix was found in higher water immersion temperature. The results of this study emphasized the importance of considering the deterioration of mechanical properties in outdoor applications of bamboo composite highly exposed to high temperature and humidity


2020 ◽  
Vol 29 (1) ◽  
pp. 3-14
Author(s):  
Kai Zhang ◽  
Wenyan Liang ◽  
Fangxin Wang ◽  
Zhenqing Wang

In this study, bamboo and glass fibers were successfully added into bisphenol A–aniline-based benzoxazine resin by hot pressing method. The effect of water absorption on the mechanical properties of the neat benzoxazine and its composites was studied. The composites prepared in this study has been proved to exhibit better water resistance than some conventional natural fiber/polymer composites due to good hydrophobicity of the benzoxazine matrix. From the mechanical tests, the tensile performance of both neat benzoxazine and the composites degraded seriously after prolonged immersion in water. However, neat benzoxazine and the composites maintained relatively higher residual flexural properties (residual mechanical properties refer to the ratio of strength and modulus of the saturated samples to that of the nonaged samples) after 20 days of water immersion. The effect of water molecules on the fracture surface morphologies of the composites was studied using a scanning electron microscope (SEM). The SEM images showed that the interfacial bonding between fibers and the matrix degraded seriously due to the attack of water.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Catarina S. P. Borges ◽  
Alireza Akhavan-Safar ◽  
Eduardo A. S. Marques ◽  
Ricardo J. C. Carbas ◽  
Christoph Ueffing ◽  
...  

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.


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.


2010 ◽  
Vol 123-125 ◽  
pp. 1031-1034 ◽  
Author(s):  
Sandhyarani Biswas ◽  
Alok Satapathy ◽  
Amar Patnaik

In order to obtain the favoured material properties for a particular application, it is important to know how the material performance changes with the filler content under given loading conditions. In this study, a series of bamboo fiber reinforced epoxy composites are fabricated using conventional filler (aluminium oxide (Al2O3) and silicon carbide (SiC) and industrial wastes (red mud and copper slag) particles as filler materials. By incorporating the chosen particulate fillers into the bamboo-fiber reinforced epoxy, synergistic effects, as expected are achieved in the form of modified mechanical properties. Inclusion of fiber in neat epoxy improved the load bearing capacity (tensile strength) and the ability to withstand bending (flexural strength) of the composites. But with the incorporation of particulate fillers, the tensile strengths of the composites are found to be decreasing in most of the cases. Among the particulate filled bamboo-epoxy composites, least value of void content are recorded for composites with silicon carbide filling and for the composites with glass fiber reinforcement minimum void fraction is noted for red mud filling. The effects of these four different ceramics on the mechanical properties of bamboo- epoxy composites are investigated and the conclusions drawn from the above investigation are discussed.


2021 ◽  
Vol 1023 ◽  
pp. 45-52
Author(s):  
Xiao Yan Wang ◽  
Meng Li ◽  
Zhi Xun Wen

After solid solution treatment at 1335°C for 4 hours and cooling to room temperature at different rate, the nickel-based single crystal superalloy were made into three kinds of nickel-based single crystal superalloy materials containing different size γ′ phases, respectively. The tensile test of I-shaped specimens was carried out at 980°C, and their effect of γ′ phase microstructure on the tensile properties was studied. The results show that the yielding strength of the material air-cooled to room temperature was lower than that with cooling rate at 0.15°C/s, but both of them were lower than the yielding strength of original material. Little difference was found on the elastic modulus of I-shaped specimens made of three kinds of materials. When the cubic degree of the γ′ phase is higher and the size is larger, the tensile properties of the material is better, which can be attributed to the larger size and narrower channel of the matrix phase that lead to higher dislocation resistance.


2005 ◽  
Vol 13 (2) ◽  
pp. 139-150 ◽  
Author(s):  
Zhanpai Su ◽  
Pingkai Jiang ◽  
Qiang Li ◽  
Ping Wei ◽  
Yong Zhang

The flame retardant and mechanical properties of polypropylene (PP), highly filled with aluminum hydroxide (Al(OH)3) and toughened with ethylene propylene diene monomer (EPDM) and zinc neutralized sulfated EPDM ionomer (Zn-S-EPDM), were studied along with their morphology. The PP matrix when highly filled with Al(OH)3 particles can achieve an adequate level of flame retardancy, but there is a decrease in the mechanical properties because of inadequate adhesion between the Al(OH)3 particles and the PP matrix and the strong tendency of the filler to agglomerate. The rubber incorporated in the PP/Al(OH)3 composites has two roles: as compatibilizer and toughening agent. Although ordinary EPDM significantly improves the Izod impact strength of the composites, the tensile properties are much worse because of the weak interfacial adhesion between the modifier and the matrix. Using Zn-S-EPDM instead EPDM, the tensile properties are much improved with only a slight decrease in toughness, because of improvements in the interfacial adhesion between modifier and matrix. SEM micrographs show that the rubber phase is dispersed in the continuous PP matrix and that most Al(OH)3 particles are uniformly distributed in the rubbery phase. Larger, obviously rubbery, domains can be seen in the PP/EPDM/Al(OH)3 ternary composites. Much finer rubbery domains were found in the PP/Zn-S-EPDM/Al(OH)3 composites.


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