scholarly journals Effect of Water Ingress on the Mechanical and Chemical Properties of Polybutylene Terephthalate Reinforced with Glass Fibers

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 ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Water Uptake ◽  
Significant Influence ◽  
Water Immersion ◽  
Water Diffusion ◽  
Polybutylene Terephthalate ◽  
Chemical Changes ◽  
Water Ingress ◽  
Effect Of Water

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.

Effect of water absorption on the mechanical properties of bamboo/glass-reinforced polybenzoxazine hybrid composite

2020 ◽  
Vol 29 (1) ◽  
pp. 3-14
Author(s):  
Kai Zhang ◽  
Wenyan Liang ◽  
Fangxin Wang ◽  
Zhenqing Wang
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Natural Fiber ◽  
Glass Fibers ◽  
Water Immersion ◽  
Mechanical Tests ◽  
Sem Images ◽  
Pressing Method ◽  
Effect Of Water ◽  
The Matrix

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.

scholarly journals The impact of molded pulp product process on the mechanical properties of molded Bleached Chemi-Thermo-Mechanical Pulp

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Claire Dislaire ◽  
Yves Grohens ◽  
Bastien Seantier ◽  
Marion Muzy
Keyword(s):  
Mechanical Properties ◽  
Water Uptake ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Water Immersion ◽  
Young Modulus ◽  
Drying Time ◽  
Mechanical Pulp ◽  
Hygroscopic Properties ◽  
The Impact

AbstractThis study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time, and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 30h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.

Water absorption effect on the in-plane shear properties of jute–glass–carbon-reinforced composites using Iosipescu test

2018 ◽  
Vol 53 (21) ◽  
pp. 3033-3045 ◽  
Author(s):  
MA Abd El-baky ◽  
MA Attia
Keyword(s):  
Water Absorption ◽  
Water Uptake ◽  
Sea Water ◽  
Water Immersion ◽  
Cost Effective ◽  
Stacking Sequence ◽  
Plane Shear ◽  
Noticeable Effect ◽  
Shear Properties ◽  
Glass Carbon

The main objective of the present paper is to study the water absorption of jute–glass–carbon-reinforced epoxy composites and its subsequent effect on the in-plane shear performance of these composites. The effects of the reinforcement hybridization, stacking sequence and relative fabric amounts on the shear behavior of dry and wet conditioned composite specimens are reported and discussed. Composites have been fabricated in inter-ply configuration using the hand lay-up process. The prepared specimens have been subjected to distilled water and sea water immersion at room temperature for 60 days. Results indicated that water uptake of jute-reinforced composite and its hybrids with glass and/or carbon follows Fickian-like behavior. Water uptake induces a significant decrease in the in-plane shear strength. Hybridizing jute fabric with glass and/or carbon fabrics improves the in-plane shear properties of both dry and wet specimens. The stacking sequence and relative fabric amounts have a noticeable effect on the studied shear properties. Also, the hybrid composite with jute as facings and glass as core, JGJ, offers the most balanced set of properties on a cost-effective basis compared to the other studied hybrids.

Effect of Water Absorption Behaviour on Tensile Properties of Hybrid Jute-Roselle Woven Fibre Reinforced Polyester Composites

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Agung Efriyo Hadi ◽  
Tezara Cionita ◽  
Deni Fajar Fitriyana ◽  
Januar Parlaungan Siregar ◽  
Ahmed Nurye Oumer ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Fibre Composite ◽  
Unsaturated Polyester ◽  
Water Immersion ◽  
Tensile Modulus ◽  
Natural Fibre ◽  
Jute Fibre ◽  
Thickness Swelling ◽  
Effect Of Water

Incorporating natural fibre as reinforcement in the polymer matrix has shown a negative effect since the natural fibre is hydrophilic. The natural fibre easily absorbs water which causes an effect on the mechanical properties of the composites. The objective of this paper is to investigate the water absorption behaviour of hybrid jute-roselle woven fibre reinforced unsaturated polyester composite and the effect of water absorption in terms of tensile strength and tensile modulus. The effect of hybrid composite on the thickness swelling will be tested. The fabrication method used in this study is the hand lay-up technique to fabricate 2-layer and 3-layer composites with layering sequences of woven jute (J)/roselle (Ro) fibre. The results of the study showed that pure roselle fibres for 2 and 3-layer composites have the highest water absorption behaviour 3.86% and 5.51%, respectively, in 28 days) as well as thickness swelling effect, whereas hybrid J-Ro and J-J-Ro composites showed the least water absorption (2.65% and 3.76%, respectively) in 28 days) in both the tests. The hybridisation between jute and roselle fibres reduced water absorption behaviour and improved the fibres dimensional stability. The entire composites showed a decreasing trend for both tensile strength and tensile modulus strength after five weeks of water immersion. Jute fibre composite hybridised with roselle fibre can be used to reduce the total reduction of both tensile strength and tensile modulus throughout the whole immersion period. Moreover, the tensile testing showed that jute fibre composite hybridised with roselle fibre have produced the strongest composite with the highest tensile and modulus strength compared to other types of composites. The hybridisation of diverse fibre reinforcements aids in minimising the composite water absorption and thickness swelling, hence reducing the effect of tensile characteristics.

scholarly journals Water Absorption and Hygrothermal Aging Behavior of Wood-Polypropylene Composites

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 782 ◽  
Author(s):  
Wei Wang ◽  
Xiaomin Guo ◽  
Defang Zhao ◽  
Liu Liu ◽  
Ruiyun Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Natural Fiber ◽  
Glass Fibers ◽  
Diffusion Constant ◽  
Water Molecules ◽  
Wood Powder ◽  
Polypropylene Composites ◽  
Effect Of Water ◽  
Composite Samples

Environmentally sound composites reinforced with natural fibers or particles interest many researchers and engineers due to their great potential to substitute the traditional composites reinforced with glass fibers. However, the sensitivity of natural fiber-reinforced composites to water has limited their applications. In this paper, wood powder-reinforced polypropylene composites (WPCs) with various wood content were prepared and subjected to water absorption tests to study the water absorption procedure and the effect of water absorbed in the specimens on the mechanical properties. Water soaking tests were carried out by immersion of composite specimens in a container of distilled water maintained at three different temperatures, 23, 60 and 80 °C. The results showed that the moisture absorption content was related to wood powder percentage and they had a positive relationship. The transfer process of water molecules in the sample was found to follow the Fickian model and the diffusion constant increased with elevated water temperature. In addition, tensile and bending tests of both dry and wet composite samples were conducted and the results indicated that water absorbed in composite specimens degraded their mechanical properties. The tensile strength and modulus of the composites reinforced with 15, 30, 45 wt % wood powder decreased by 5.79%, 17.2%, 32.06% and 25.31%, 33.6%, 47.3% respectively, compared with their corresponding dry specimens. The flexural strength and modulus of the composite samples exhibited a similar result. Furthermore, dynamic mechanical analysis (DMA) also confirmed that the detrimental effect of water molecules on the composite specimens.

Modeling of water diffusion mechanism in polypropylene/date palm fiber composite materials

2018 ◽  
Vol 52 (19) ◽  
pp. 2651-2659 ◽  
Author(s):  
Sonia Boukettaya ◽  
Ahmad Alawar ◽  
Fahad Almaskari ◽  
Hachmi Ben Daly ◽  
Ahmed Abdala ◽  
...  
Keyword(s):  
Composite Materials ◽  
Water Absorption ◽  
Date Palm ◽  
Fiber Composite ◽  
Water Immersion ◽  
Diffusion Mechanism ◽  
Water Diffusion ◽  
Uptake Mechanism ◽  
Absorption Mechanism ◽  
Date Palm Fibers

The aim of this work is to model the water absorption mechanism of the polypropylene/date palm fibers composite materials after their exposure at different immersion conditions. For short immersion period, a model combining the Fick’s law and the time temperature stress principle has been proposed to describe the water absorption mechanism. However, it has been noted that, after a saturation time, the water diffusion mechanism leads to a physical degradation and a mass loss into the composite material, especially under high temperatures and long times of water immersion. Microscopic observations have revealed a decrease of the interfacial adhesion between the fibers and the matrix and fiber degradations. A general new model describing the evolution of the water uptake mechanism and the degradation phenomenon has been also proposed in the present work. A good agreement between the theoretical and experimental data has been obtained.

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
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Tensile Properties ◽  
Water Immersion ◽  
Bamboo Fiber ◽  
Epoxy Composites ◽  
Gravimetric Analysis ◽  
Sorption Behaviour ◽  
Laminated Bamboo ◽  
The Matrix

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.

Effect of water absorption on the mechanical properties of cross-ply hybrid pseudo- stem banana/glass fibre reinforced polypropylene composite

2019 ◽  
Vol 6 (9) ◽  
pp. 095326 ◽  
Author(s):  
Norizzati Zulkafli ◽  
Sivakumar Dhar Malingam ◽  
Siti Hajar Sheikh Md Fadzullah ◽  
Zaleha Mustafa ◽  
Kamarul Ariffin Zakaria ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Glass Fibre ◽  
Polypropylene Composite ◽  
Effect Of Water ◽  
Glass Fibre Reinforced
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