scholarly journals Halloysite reinforced epoxy composites with improved mechanical properties

2016 ◽  
Vol 18 (1) ◽  
pp. 133-135 ◽  
Author(s):  
Muhammad Jawwad Saif ◽  
Muhammad Asif ◽  
Muhammad Naveed ◽  
Khalid Mahmood Zia ◽  
Waheed -uz- Zaman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Halloysite Nanotubes ◽  
Epoxy Composites ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Interfacial Coupling ◽  
Uniform Dispersion

Abstract Halloysite nanotubes (HNTs) reinforced epoxy composites with improved mechanical properties were prepared. The prepared HNTs reinforced epoxy composites demonstrated improved mechanical properties especially the fracture toughness and flexural strength. The flexural modulus of nanocomposite with 6% mHNTs loading was 11.8% higher than that of neat epoxy resin. In addition, the nanocomposites showed improved dimensional stability. The prepared halloysite reinforced epoxy composites were characterized by thermal gravimetric analysis (TGA). The improved properties are attributed to the unique characteristics of HNTs, uniform dispersion of reinforcement and interfacial coupling.

scholarly journals Mechanical Characterization of Epoxy Filled with Seed Shells as Reinforcement

2019 ◽  
Vol 8 (4) ◽  
pp. 6972-6977
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Sodium Hydroxide ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Flexural Modulus ◽  
Natural Fibers ◽  
Epoxy Composites ◽  
The Matrix ◽  
Sunflower Seed Shells

The use of natural fiber composite has been widely promoted in many industries such as construction, automotive and even aerospace. Natural fibers can be extracted from plants that are abundantly available in the form of waste such as sunflower seed shells (SSS) and groundnut shells (GNS). These fibers were chosen as the reinforcement in epoxy to form composites. The performance of composites was evaluated following the ASTM D3039 and ASTM D790 for tensile and flexural tests respectively. Eight types of composites were prepared using SSS and GNS fibers as reinforcement and epoxy as the matrix with the fiber content of 20wt %. The fibers were untreated and treated with Sodium Hydroxide (NaOH) at various concentrations (6%, 10%, 15%, and 20%) and soaking time (24, 48 and 72 hours). The treatment has successfully enhanced the mechanical properties of both composites, namely SSS/epoxy and GNS/epoxy composites. The SSS/epoxy composite has the best mechanical properties when the fibers were treated for 48 hours using 6% of NaOH that produced 22 MPa and 13 MPa of tensile and flexural strength respectively. Meanwhile, the treatment on groundnut shells with 10% sodium Hydroxide for 24 hours has increased the Flexural strength tremendously (53%), however no significant effect on the tensile strength. The same trend was also observed on the tensile and flexural modulus. The increase of 41% in flexural modulus after treatment with 10% NaOH for 24 hours was also the evidence of mechanical properties enhancement. The evidence of improved fiber and matrix bonding after fiber treatment was also observed using a scanning electron microscope (SEM). The SSS/epoxy composites performed better in tensile application, meanwhile the GNS/epoxy composites are good in flexural application.

The Influence of Functionalized TiO2 with Poly(methyl methacrylate) on the Mechanical Properties of TiO2/Epoxy Nanocomposites

2011 ◽  
Vol 415-417 ◽  
pp. 297-301
Author(s):  
Hong Bo Liang ◽  
Lei Xiong ◽  
Hai Tao Xu ◽  
Jing Guan
Keyword(s):  
Mechanical Properties ◽  
Methyl Methacrylate ◽  
Bending Strength ◽  
Impact Testing ◽  
Epoxy Composites ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
1H Nuclear Magnetic Resonance ◽  
Ft Ir ◽  
The Impact

The functionalized TiO2 with poly(methyl methacrylate) (TiO2-PMMA) was prepared by atom transfer radical polymerization (ATRP), and its reinforcement for epoxy composites was studied. The functionalized TiO2 was characterized by Fourier transform infrared (FT-IR), Thermal gravimetric analysis (TGA) and 1H nuclear magnetic resonance (NMR). The properties of nanocomposites were measured by impact testing, bending experiment and Scanning electron microscopy (SEM). Because of the grafting of PMMA and the higher interaction between TiO2-PMMA and epoxy matrix, the composites exhibited the enhancement of mechanical properties at lower content. As the functionalized TiO2 content is 0.5 wt%, the impact strength and bending strength of composite increased nearly 142% and 37%, respectively, compared to the neat epoxy resin.

scholarly journals Investigating the Mechanical Properties of ZrO2-Impregnated PMMA Nanocomposite for Denture-Based Applications

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1344 ◽  
Author(s):  
Saleh Zidan ◽  
Nikolaos Silikas ◽  
Abdulaziz Alhotan ◽  
Julfikar Haider ◽  
Julian Yates
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Impact Strength ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Surface Hardness ◽  
Bending Test ◽  
Zro2 Nanoparticles ◽  
Control Group ◽  
The Mean

Acrylic resin PMMA (poly-methyl methacrylate) is used in the manufacture of denture bases but its mechanical properties can be deficient in this role. This study investigated the mechanical properties (flexural strength, fracture toughness, impact strength, and hardness) and fracture behavior of a commercial, high impact (HI), heat-cured denture base acrylic resin impregnated with different concentrations of yttria-stabilized zirconia (ZrO2) nanoparticles. Six groups were prepared having different wt% concentrations of ZrO2 nanoparticles: 0% (control), 1.5%, 3%, 5%, 7%, and 10%, respectively. Flexural strength and flexural modulus were measured using a three-point bending test and surface hardness was evaluated using the Vickers hardness test. Fracture toughness and impact strength were evaluated using a single edge bending test and Charpy impact instrument. The fractured surfaces of impact test specimens were also observed using a scanning electron microscope (SEM). Statistical analyses were conducted on the data obtained from the experiments. The mean flexural strength of ZrO2/PMMA nanocomposites (84 ± 6 MPa) at 3 wt% zirconia was significantly greater than that of the control group (72 ± 9 MPa) (p < 0.05). The mean flexural modulus was also significantly improved with different concentrations of zirconia when compared to the control group, with 5 wt% zirconia demonstrating the largest (23%) improvement. The mean fracture toughness increased in the group containing 5 wt% zirconia compared to the control group, but it was not significant. However, the median impact strength for all groups containing zirconia generally decreased when compared to the control group. Vickers hardness (HV) values significantly increased with an increase in ZrO2 content, with the highest values obtained at 10 wt%, at 0 day (22.9 HV0.05) in dry conditions when compared to the values obtained after immersing the specimens for seven days (18.4 HV0.05) and 45 days (16.3 HV0.05) in distilled water. Incorporation of ZrO2 nanoparticles into high impact PMMA resin significantly improved flexural strength, flexural modulus, fracture toughness and surface hardness, with an optimum concentration of 3–5 wt% zirconia. However, the impact strength of the nanocomposites decreased, apart from the 5 wt% zirconia group.

Mechanical Properties and Fracture Toughness of Alkali Treated Oil Palm Fruit Bunch (OPFB) Fibre/Epoxy Composites

2013 ◽  
Vol 390 ◽  
pp. 521-525
Author(s):  
Anizah Kalam ◽  
Aidah Jumahat ◽  
Z. Salleh ◽  
Koay Mei Hyie
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Oil Palm ◽  
Alkali Treatment ◽  
Epoxy Composites ◽  
Palm Fruit ◽  
Fibre Composites ◽  
Fracture Tests

Mechanical properties of oil palm fruit bunch (OPFB) fibre composites have been quite extensively research by many researchers. However fracture toughness of this composite is still not fully understood. Hence this research used Sodium hydroxide (NaOH) at three different concentrations (1%, 3% and 5%) to treat the Oil palm fruit bunch (OPFB) fibre to investigate the effects of alkali treatment on the mechanical properties and facture toughness of OPFB fibre/epoxy composites. Tensile and fracture tests results indicate that the 3% NaOH concentration gave the best mechanical properties. An increase of 12% and 18% were observed for tensile and flexural moduli, meanwhile the increament of 9% was observed for tensile strength. However no increase on flexural strength was observed due to the OPFB treatment. Suggestion has been made to further study on the NaOH concentration in the range of 2% - 4%.

Degradation of Mechanical Properties of Conventional and Nanophased Carbon/Epoxy Composites in Seawater

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
M. K. Hossain ◽  
K. A. Imran ◽  
M. V. Hosur ◽  
S. Jeelani
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Microscopy Study ◽  
Epoxy Composites ◽  
Molding Process ◽  
Bending Tests ◽  
Three Point Bending ◽  
Degradation Of Mechanical Properties ◽  
Marine Applications

Composites used for marine applications are subjected to various environmental effects, such as moisture, temperature, UV radiation, and seawater. In this study, effect of seawater on the degradation of mechanical properties of conventional and nanophased carbon/epoxy composites was investigated. Epoxy resin was modified using 1 wt. %, 2 wt. %, and 3 wt. % nanoclay. Carbon/epoxy composites were fabricated by vacuum assisted resin transfer molding process and compared with neat samples with and without exposure to seawater. Nanoclay was dispersed into matrix by using magnetic stirring. Mechanical characterization performed through three point bending tests showed that 2 wt. % nanoclay loading was optimum. Flexural strength and modulus were increased by 25% and 12.51%, respectively, compared to neat system for samples not exposed to seawater. Flexure samples exposed to the seawater for 30-, 60-, and 180-day periods revealed that samples with nanoclay retained better mechanical properties compared to neat samples. After 30-day exposure to seawater, there was no significant reduction in the strength and modulus. However, flexural strength was reduced by 10.24%, 7.08%, 5.28%, and 7.13% for neat, 1 wt. %, 2 wt. %, and 3 wt. % nanoclay-infused samples, respectively, after the samples were exposed to seawater for 180-day. At the same time flexural modulus was reduced by 12.61%, 7.16%, 4.59%, and 6.11%, respectively. From scanning electron microscopy (SEM) studies, it was found that failure occurred due to delimitation and initiated from the compression side. Nanophased composites exhibited better bonding between fiber and matrix. SEM micrographs also revealed that both unconditioned and conditioned nanophased epoxy, which produce relatively rougher fracture surfaces compared to neat samples. Optical microscopy study revealed no significant physical change in outer surfaces of the samples conditioned up to a 90-day period.

scholarly journals Effect of Morphology of Calcium Carbonate on Toughness Behavior and Thermal Stability of Epoxy-Based Composites

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 178 ◽  
Author(s):  
Guijun Yang ◽  
Young-Jung Heo ◽  
Soo-Jin Park
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Filler Content ◽  
Flexural Modulus ◽  
Epoxy Composites ◽  
Neat Epoxy ◽  
Caco3 Nanoparticles ◽  
Degradation Temperature ◽  
Thermal Stability Of

In this study, the modification of an epoxy matrix with different amounts of cube-like and rod-like CaCO3 nanoparticles was investigated. The effects of variations in the morphology of CaCO3 on the mechanical properties and thermal stability of the CaCO3/epoxy composites were studied. The rod-like CaCO3/epoxy composites (EP-rod) showed a higher degradation temperature (4.5 °C) than neat epoxy. The results showed that the mechanical properties, such as the flexural strength, flexural modulus, and fracture toughness of the epoxy composites with CaCO3 were enhanced by the addition of cube-like and rod-like CaCO3 nanoparticles. Moreover, the mechanical properties of the composites were enhanced by increasing the amount of CaCO3 added but decreased when the filler content reached 2%. The fracture toughness Kic and fracture energy release rate Gic of cube-like and rod-like CaCO3/epoxy composites (0.85/0.74 MPa m1/2 and 318.7/229.5 J m−2, respectively) is higher than the neat epoxy (0.52 MPa m1/2 and 120.48 J m−2).

scholarly journals The Mechanical Properties of Kevlar Fabric/Epoxy Composites Containing Aluminosilicates Modified with Quaternary Ammonium and Phosphonium Salts

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3726 ◽  
Author(s):  
Rafał Oliwa
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Quaternary Ammonium ◽  
Flexural Modulus ◽  
Sem Analysis ◽  
Epoxy Composites ◽  
Phosphonium Salts ◽  
Plane Shear ◽  
Modified Bentonite ◽  
Uniform Dispersion

We investigated the effect of modified aluminosilicates, including bentonite from Armenia (BA) modified with quaternary ammonium salts (BAQAS) and phosphonium salts (BAQPS), on the mechanical properties and morphology of Kevlar/epoxy composites. The Kevlar/epoxy composites containing 1.0 or 3.0 wt.% modified bentonites were fabricated using the hand lay-up technique. The mechanical properties, including the tensile, flexural, and in-plane shear strength, were tested. Based on the obtained results, we found that the mechanical properties increased with modified bentonite loading. The best results were obtained for composites containing 3 wt.% BAQAS, as most of the mechanical properties were significantly improved (tensile strength 302.9 MPa (+30%), Young’s modulus 16.3 GPa (+17%), flexural modulus 23.4 GPa (+12.5%), in-plane shear strength 22.8 MPa (+24.5%), and in-plane shear modulus 677.2 MPa (+42%)). The obtained improvements in the mechanical properties are attributed to the uniform dispersion of the filler, which was confirmed by the highest increase in the intergallery spacing, from 28.3 Å for BAQAS to 45.1 Å for the composite with 3 wt.% BAQAS. Scanning electron microscopy (SEM) analysis of the brittle fracture surface indicated that the addition of modified bentonite to the epoxy matrix changed the morphology of the Kevlar/epoxy/organoclay composites and improved the fiber–matrix interfacial adhesion.

Mechanical and Physical Properties of Recycled Cellulose Fibre-Reinforced Epoxy Eco-Composites

2008 ◽  
Vol 41-42 ◽  
pp. 317-322 ◽  
Author(s):  
J. Sommers ◽  
H.S. Kho ◽  
R. Al-Ghamedi ◽  
It Meng Low ◽  
Ian J. Davies ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Impact Toughness ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Cellulose Fibre ◽  
Epoxy Composites ◽  
Ex Situ ◽  
Moderate Increase ◽  
Mechanical And Physical Properties

Epoxy composites reinforced with recycled cellulose fibre (RCF) have been synthesized and characterized. The reinforcement by RCF has resulted in a significant increase in the strain at break, fracture toughness and impact toughness but moderate increase in flexural strength and flexural modulus. The effect of seawater soaking on the flexural and impact properties has also been investigated. The micromechanisms of toughening and crack-tip failure processes are identified and discussed in the light of observed microstructures from in-situ and ex-situ fracture.

scholarly journals Effect of Clay Addition on Mechanical Properties of Unsaturated Polyester/Glass Fiber Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Kusmono ◽  
Zainal Arifin Mohd Ishak
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Unsaturated Polyester ◽  
Flexural Modulus ◽  
Charpy Impact ◽  
Fiber Composites ◽  
Glass Fiber Composites

Unsaturated polyester (UP)/glass fiber/clay composites were prepared by hand layup method. The effect of clay loading on the morphological and mechanical properties of UP/glass fiber composites was investigated in this study. X-ray diffraction (XRD) was used to characterize the structure of the composites. The mechanical properties of the composites were determined by tensile, flexural, unnotched Charpy impact and fracture toughness tests. XRD results indicated that the exfoliated structure was found in the composite containing 2 wt% of clay while the intercalated structure was obtained in the composite with 6 wt% of clay. The tensile strength, flexural strength, and flexural modulus of the composites were increased in the presence of clay. The optimum loading of clay in the UP/glass fiber composites was attained at 2 wt%, where the improvement in in tensile strength, flexural strength, and flexural modulus was approximately 13, 21, and 11%, respectively. On the other hand, the highest values in impact toughness and fracture toughness were observed in the composites with 4 wt% of clay.

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