The Effect of Water Absorption on Mechanical Properties of Wood Flour/Wheat Husk Polypropylene Hybrid Composites

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.

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Effects of water absorption on the mechanical properties of hybrid natural fibre/phenol formaldehyde composites

Scientific Reports ◽

10.1038/s41598-021-92457-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sekar Sanjeevi ◽

Vigneshwaran Shanmugam ◽

Suresh Kumar ◽

Velmurugan Ganesan ◽

Gabriel Sas ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Impact Strength ◽

Water Absorption ◽

Hybrid Composites ◽

Phenol Formaldehyde ◽

Natural Fibre ◽

The Other ◽

Fibre Reinforcement ◽

Dry Conditions

AbstractThis investigation is carried out to understand the effects of water absorption on the mechanical properties of hybrid phenol formaldehyde (PF) composite fabricated with Areca Fine Fibres (AFFs) and Calotropis Gigantea Fibre (CGF). Hybrid CGF/AFF/PF composites were manufactured using the hand layup technique at varying weight percentages of fibre reinforcement (25, 35 and 45%). Hybrid composite having 35 wt.% showed better mechanical properties (tensile strength ca. 59 MPa, flexural strength ca. 73 MPa and impact strength 1.43 kJ/m2) under wet and dry conditions as compared to the other hybrid composites. In general, the inclusion of the fibres enhanced the mechanical properties of neat PF. Increase in the fibre content increased the water absorption, however, after 120 h of immersion, all the composites attained an equilibrium state.

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Investigations on the Mechanical Properties of Glass Fiber/Sisal Fiber/Chitosan Reinforced Hybrid Polymer Sandwich Composite Scaffolds for Bone Fracture Fixation Applications

Polymers ◽

10.3390/polym12071501 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1501 ◽

Cited By ~ 4

Author(s):

Soundhar Arumugam ◽

Jayakrishna Kandasamy ◽

Ain Umaira Md Shah ◽

Mohamed Thariq Hameed Sultan ◽

Syafiqah Nur Azrie Safri ◽

...

Keyword(s):

Mechanical Properties ◽

Water Absorption ◽

Glass Fiber ◽

Bone Fracture ◽

Hybrid Composite ◽

Bone Structure ◽

Hybrid Composites ◽

Sisal Fiber ◽

Composite Scaffolds ◽

Study Results

This study aims to explore the mechanical properties of hybrid glass fiber (GF)/sisal fiber (SF)/chitosan (CTS) composite material for orthopedic long bone plate applications. The GF/SF/CTS hybrid composite possesses a unique sandwich structure and comprises GF/CTS/epoxy as the external layers and SF/CTS/epoxy as the inner layers. The composite plate resembles the human bone structure (spongy internal cancellous matrix and rigid external cortical). The mechanical properties of the prepared hybrid sandwich composites samples were evaluated using tensile, flexural, micro hardness, and compression tests. The scanning electron microscopic (SEM) images were studied to analyze the failure mechanism of these composite samples. Besides, contact angle (CA) and water absorption tests were conducted using the sessile drop method to examine the wettability properties of the SF/CTS/epoxy and GF/SF/CTS/epoxy composites. Additionally, the porosity of the GF/SF/CTS composite scaffold samples were determined by using the ethanol infiltration method. The mechanical test results show that the GF/SF/CTS hybrid composites exhibit the bending strength of 343 MPa, ultimate tensile strength of 146 MPa, and compressive strength of 380 MPa with higher Young’s modulus in the bending tests (21.56 GPa) compared to the tensile (6646 MPa) and compressive modulus (2046 MPa). Wettability study results reveal that the GF/SF/CTS composite scaffolds were hydrophobic (CA = 92.41° ± 1.71°) with less water absorption of 3.436% compared to the SF/CTS composites (6.953%). The SF/CTS composites show a hydrophilic character (CA = 54.28° ± 3.06°). The experimental tests prove that the GF/SF/CTS hybrid composite can be used for orthopedic bone fracture plate applications in future.

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Water Absorption and Hygrothermal Aging Behavior of Wood-Polypropylene Composites

Polymers ◽

10.3390/polym12040782 ◽

2020 ◽

Vol 12 (4) ◽

pp. 782 ◽

Cited By ~ 2

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.

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Effect of water absorption on the mechanical properties of hybrid interwoven cellulosic-cellulosic fibre reinforced epoxy composites

Composite Structures ◽

10.1016/j.compstruct.2017.02.023 ◽

2017 ◽

Vol 167 ◽

pp. 227-237 ◽

Cited By ~ 58

Author(s):

A.B. Maslinda ◽

M.S. Abdul Majid ◽

M.J.M. Ridzuan ◽

M. Afendi ◽

A.G. Gibson

Keyword(s):

Mechanical Properties ◽

Water Absorption ◽

Epoxy Composites ◽

Cellulosic Fibre ◽

Effect Of Water

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

Materials Research Express ◽

10.1088/2053-1591/ab3203 ◽

2019 ◽

Vol 6 (9) ◽

pp. 095326 ◽

Cited By ~ 6

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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Hybrid Composites Based on Polypropylene with Basalt/Hazelnut Shell Fillers: The Influence of Temperature, Thermal Aging, and Water Absorption on Mechanical Properties

Polymers ◽

10.3390/polym12010018 ◽

2019 ◽

Vol 12 (1) ◽

pp. 18 ◽

Cited By ~ 2

Author(s):

Anna Kufel ◽

Stanisław Kuciel

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Water Absorption ◽

Thermal Aging ◽

Hybrid Composites ◽

Coefficient Of Thermal Expansion ◽

Tensile Modulus ◽

Charpy Impact ◽

Creep Tests ◽

Influence Of Temperature

The aim of the research was to study the effects of adding natural fillers to a polypropylene (PP) matrix on mechanical and physical properties of hybrid composites. The 10%, 15%, and 20% by weight basalt fibers (BF) and ground hazelnut shells (HS) were added to the PP matrix. Composites were produced by making use of an injection molding method. Tensile strength, tensile modulus, strain at break, Charpy impact strength, and the coefficient of thermal expansion were determined. The influence of temperature, thermal aging, and water absorption on mechanical properties was also investigated. In addition, short-time creep tests were carried out. To characterize the morphology and the filler distribution within the matrix, a scanning electron microscope (SEM) was used. The results showed that the addition of the two types of filler enhanced mechanical properties. Furthermore, improvements in thermal stability were monitored. After water absorption, the changes in the tensile properties of the tested composites were moderate. However, thermal aging caused a decrease in tensile strength and tensile modulus.

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