Enhanced Thermal and Mechanical Properties of Epoxy Composites by Spherical Silica with Different Size

2017 ◽  
Vol 727 ◽  
pp. 519-526 ◽  
Author(s):  
Li Ya Chen ◽  
Ji Fang Fu ◽  
Wen Qi Yu ◽  
Lei Huang ◽  
Jing Tao Yin ◽  
...  
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Impact Strength ◽  
Flexural Modulus ◽  
Silica Particles ◽  
Epoxy Composites ◽  
Pure Epoxy ◽  
Spherical Silica ◽  
Spherical Silica Particles ◽  
The Impact

Spherical silica particles with mean diameter 350 nm, 500 nm and 1000 nm were used to modify o-cresol-novolac epoxy resin (ECN) at a ranging constant weight fraction from 0 to 20 wt%. The effects of particle size and fillers content on the impact strength, flexural modulus, dynamic mechanical analysis (DMA), coefficient of thermal expansion (CTE), dielectric properties and bulk resistivities of epoxy composites filled with spherical silica particles were investigated. The results revealed that the impact strength and flexural modulus showed significant improvements with the addition of spherical silica particles. The glass transition temperature (Tg) of composites was higher than that of pure epoxy. The maximum increment of Tg was 34 °C by the addition of 2 wt% D500. The CTE of the composites with different size silica exhibit much lower dimension changes than that of pure epoxy. The dielectric constant was decreased with the addition of spherical silica particles. However, the particle size exhibited weakly effect on the dielectric properties. The bulk resistivities of the composites have greatly improved compared to the pure epoxy and increase with decreasing the particle size.

Effects of Weave Type and Fiber Content on Physical Properties of Sisal Fiber/Epoxy Composites

2010 ◽  
Vol 123-125 ◽  
pp. 1139-1142 ◽  
Author(s):  
Sawitri Srisuwan ◽  
Pranee Chumsamrong
Keyword(s):  
Impact Strength ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Flexural Modulus ◽  
Fiber Content ◽  
Epoxy Composites ◽  
Sisal Fiber ◽  
Pure Epoxy ◽  
Sisal Fibers ◽  
The Impact

In this study, the effects of weave type and fiber content on the physical properties of woven sisal fiber/epoxy composites were investigated. Sisal fibers used in this work were obtained from Nakhon Ratchasima, Thailand. Both untreated and alkali-treated fibers were employed. The woven sisal fibers were manufactured by hand weaving process. The fiber content in sisal fiber/epoxy composites were 3 wt.%, 5 wt.% and 10 wt.%. The composites were cured at room temperatures. In order to determine mechanical properties of the composites, flexural and impact tests were applied. Flexural strength and flexural modulus of all composites were higher than those of pure epoxy resin and tended to increase with increasing fiber content. The impact strength of all composites was lower than that of pure epoxy resin. The composites containing 10 wt.% sisal fibers showed the highest impact strength. There was no definite influence of weave type on flexural properties of the composites. At 3 and 5 wt.% fiber, the composites containing plain weave fibers seemed to show a higher impact strength than the composites containing other weave types.

Controlling Factors of the Particle Size of Spherical Silica Synthesized by Wet and Dry Processes

2021 ◽  
Vol 6 (7) ◽  
pp. 118-121
Author(s):  
Keiji Saiki ◽  
Toshihiro Ishikawa
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Silica Particles ◽  
Controlling Factors ◽  
Dry Process ◽  
Wet Process ◽  
Spherical Silica ◽  
Wide Range ◽  
Spherical Silica Particles ◽  
Trimethoxy Silane

We clarified the controlling factors of the particle size of the amorphous silica synthesized by wet and dry processes. In the wet process using methyl-trimethoxy-silane as a starting monomer, the obtained particle size can be easily controlled by changing the reaction time appropriately. However, to obtain larger particles, a relatively long time is needed. After the condensation reaction was conducted for 50h, the silica particles (D50: 3μm) were synthesized by calcination at 550oC in air. To synthesize larger silica particles, we used silica-seed particles (8μm) to obtain very large spherical silica particles (D50: 20μm). Thus, although the wet process needs a relatively long reaction time, it is very useful for synthesizing spherical silica particles with a wide range of particle size. In the dry process, we used methyl-trimethoxy-silane (MTMS), tetra-ethoxy-silane (TEOS), and octamethyl-cyclotetrasiloxane (OMCTSO) as the starting materials. In this process, the size of the silica particles was dominated by the molecular structure of the monomer, in particular, the number of silicon atoms contained in the monomer and the bulkiness of the substituent group. The largest silica particles were synthesized from OMCTSO, which contains the largest number of silicon atoms.

Preparation of Spherical Silica with Controllable Size

2018 ◽  
Vol 281 ◽  
pp. 65-70
Author(s):  
Shu Lin Wang ◽  
Zhao Wang ◽  
Bing Hao Li ◽  
Man Xu
Keyword(s):  
Particle Size ◽  
Silica Particle ◽  
Sol Gel ◽  
Silica Particles ◽  
Spherical Particles ◽  
Alkali Content ◽  
Spherical Silica ◽  
Hydrolysis Temperature ◽  
Spherical Silica Particles ◽  
Size And Morphology

The spherical silica particles were prepared by sol-gel method with TEOS as precursor, ethanol as solvent in the presence of ammonia. The effects of reaction temperature and the amount of ammonia and TEOS on the size and morphology of silica particles were investigated. The hydrolysis temperature , alkali and TEOS content does not affect the morphology of silica, the silica particles were spherical; With the increase of hydrolysis temperature, particle size of silica showed first increased and then decreased, when the hydrolysis temperature is 30 °C, the silica particle size up to 0.6 μm, when the hydrolysis temperature is 60 °C, the silica particle size is 0.15 μm; With the increase of the content of alkali, silica particle size showed first increased and then decreased, when the alkali content is 20 ml, the silica particle size up to 0.6 μm and when the alkali content is 10 ml, the silica particle size is 0.2 μm; With the increase of TEOS dosage, the amount of spherical silica increased and the particle size of silica spherical particles first increased and then decreased.

scholarly journals PENGARUH UKURAN PARTIKEL DAN KOMPOSISI TERHADAP SIFAT KEKUATAN BENTUR KOMPOSIT EPOKSI BERPENGISI SERAT DAUN NANAS

2014 ◽  
Vol 3 (3) ◽  
pp. 13-17
Author(s):  
Syahrinal Anggi Daulay ◽  
Fachry Wirathama ◽  
Halimatuddahliana
Keyword(s):  
Particle Size ◽  
Impact Strength ◽  
Volume Fraction ◽  
Size Variation ◽  
Sem Analysis ◽  
Epoxy Composites ◽  
Pineapple Leaf Fiber ◽  
The Impact ◽  
Filler Distribution ◽  
Leaf Fiber

This research was aimed to investigate the effect of pineapple leafs particle size and pineapple leaf fiber composition of the impact strength of epoxy composites filled with pineapple leaf fibers. The composites were made by hand lay up method by mixing epoxy and pineapple leaf fiber with particle size variation of 30 mesh, 40 mesh, 70 mesh, 100 mesh, and volume fraction ratio between filler and matrix 5/95, 10/90, 15/85 (v/v). Mechanical properties wich tested was impact strength and  supported with SEM analysis. The results obtained show that the addition pineapple leaf fiber as filler in epoxy composites generally increase the impact strength of the composites, with best performance shown by 100 mesh particle size variation with ratio 90/10 (v/v) which from SEM analysis show that this variation having better filler distribution.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

2020 ◽  
Vol 38 (7A) ◽  
pp. 960-966
Author(s):  
Aseel M. Abdullah ◽  
Hussein Jaber ◽  
Hanaa A. Al-Kaisy
Keyword(s):  
Impact Strength ◽  
Wear Rate ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Weight Fraction ◽  
Pure Pmma ◽  
Calcination Process ◽  
The Matrix ◽  
The Impact ◽  
Interface Bond

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

scholarly journals Design, synthesis, and catalytic performance of modified graphene oxide based on a cobalt complex as a heterogenous catalyst for the preparation of aminonaphthoquinone derivatives

RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17108-17115
Author(s):  
Mahnaz Mirheidari ◽  
Javad Safaei-Ghomi
Keyword(s):  
Graphene Oxide ◽  
Cobalt Complex ◽  
Catalytic Performance ◽  
Silica Particles ◽  
Design Synthesis ◽  
Spherical Silica ◽  
Modified Graphene Oxide ◽  
Spherical Silica Particles ◽  
Heterogenous Catalyst ◽  
Modified Graphene

GO@f-SiO2@Co is a heterogenous catalyst composed of spherical silica particles grafted on the surface of graphene oxide with ethylenediamine ligands and coordination with Co(ii). We assessed the activity of the catalyst for the synthesis of aminonaphthoquinones.

scholarly journals Enhanced flexural properties of aramid fiber/epoxy composites by graphene oxide

2019 ◽  
Vol 8 (1) ◽  
pp. 484-492 ◽  
Author(s):  
Yinqiu Wu ◽  
Bolin Tang ◽  
Kun Liu ◽  
Xiaoling Zeng ◽  
Jingjing Lu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Flexural Strength ◽  
Interfacial Shear Strength ◽  
Flexural Modulus ◽  
Weight Fraction ◽  
Interfacial Shear ◽  
Aramid Fiber ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Pure Epoxy

Abstract The reinforcing effect of graphene oxide (GO) in enhancing the flexural strength and flexural modulus of aramid fiber (AF)/epoxy composites were investigated with GO-AFs at a weight fraction of 0.1-0.7%. The flexural strength and flexural modulus of the composite reached 87.16 MPa and 1054.7 MPa, respectively, which were about 21.19% and 40.86% higher than those of the pure epoxy resin, respectively. In addition, the flexural properties and interfacial shear strength (IFSS) of composite reinforced by GO-AFs were much higher than the composites reinforced by AFs due to GO improved the interfacial bonding between the reinforcement material and matrix.

Hybrid effects of carbon fiber and nanoclay as fillers on the performances of recycled wood-plastic composites

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7671-7686
Author(s):  
Young-Rok Seo ◽  
Sang-U Bae ◽  
Birm-June Kim ◽  
Min Lee ◽  
Qinglin Wu
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Carbon Fibers ◽  
Synergistic Effects ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Raw Material ◽  
Scanning Electron Micrographs ◽  
Plastic Composite ◽  
The Impact

Waste wood-plastic composite (WPC) was used in this work as a raw material to produce recycled WPCs reinforced with carbon fiber and nanoclay. To evaluate the synergistic effects of carbon fiber and nanoclay, various performances (i.e., microstrucural, mechanical, thermal, water absorption, and electrical properties) were investigated. Scanning electron micrographs and X-ray diffraction analysis of the fillers (carbon fiber and nanoclay) present in the recycled WPCs showed that the nanoclays were properly intercalated when filled with carbon fibers. According to mechanical property analysis, hybrid incorporation of carbon fibers and nanoclays improved impact strength, tensile strength, and flexural strength. However, further incorporation of nanoclays reduced the impact strength and did not improve the tensile modulus or the flexural modulus. The carbon fibers present in the recycled WPCs improved the electrical conductivity of the composites, despite the various fillers that interfered with their electrical conduction. In addition, carbon fibers and nanoclays were mixed into the recycled WPCs to improve the thermal stability of the composites. Finally, the presence of nanoclays in recycled WPCs led to increased water uptake of the composites.

scholarly journals Characterization of Hybrid Oil Palm Empty Fruit Bunch/Woven Kenaf Fabric-Reinforced Epoxy Composites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2052
Author(s):  
Farah Hanan ◽  
Mohammad Jawaid ◽  
Md Tahir Paridah ◽  
Jesuarockiam Naveen
Keyword(s):  
Impact Strength ◽  
Oil Palm ◽  
Failure Modes ◽  
Fiber Content ◽  
Epoxy Composites ◽  
Void Content ◽  
Empty Fruit Bunch ◽  
Kenaf Fiber ◽  
The Impact ◽  
Woven Kenaf

In this research, the physical, mechanical and morphological properties of oil palm empty fruit bunch (EFB) mat/woven kenaf fabric-reinforced epoxy composites have been investigated. The oil palm EFB/woven kenaf fabrics were varied, with weight ratios of 50/0 (T1), 35/15 (T2), 25/25 (T3), 15/35 (T4) and 0/50 (T5). The composites were fabricated using a simple hand lay-up technique followed by hot pressing. The result obtained shows that an increase in kenaf fiber content exhibited higher tensile and flexural properties. On the other hand, the opposite trend was observed in the impact strength of hybrid composites, where an increase in kenaf fiber content reduced the impact strength. This can be corroborated with the physical properties analysis, where a higher void content, water absorption and thickness swelling were observed for pure oil palm EFB (T1) composites compared to other samples. The scanning electron microscopy analysis results clearly show the different failure modes of the tensile fractured samples. Statistical analysis was performed using one-way ANOVA and shows significant differences between the obtained results.

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