scholarly journals Epoxy composites with increased operational characteristics, filled with dispersed mineral fillers

2018 ◽  
Vol 80 (3) ◽  
pp. 330-335
Author(s):  
A. S. Mostovoi ◽  
A. S. Nurtazina ◽  
Yu. A. Kadykova
Keyword(s):  
Impact Strength ◽  
Heat Resistance ◽  
Epoxy Resin ◽  
Oxygen Index ◽  
Epoxy Composite ◽  
Tensile Modulus ◽  
Epoxy Composites ◽  
Breaking Stress ◽  
Mineral Fillers ◽  
The Impact

The aim of this work is to increase the physicochemical, deformation and strength properties and to reduce the combustibility of composites on the base of epoxy resin by introducing a oligo(resorcinophenyl phosphate) with terminal phenyl groups Fyrolflex - modifier of polyfunctional action, and disperse mineral fillers – diorite and chromite. Result of the studies established that the optimum amount of modifier in the composition of the epoxy resin is 40 mass parts, which provides an increase in the operational properties of the composites: the breaking stress at bending increases by 2 times, the breaking stress at compression increases by 28%, the impact strength increases twice, while the modulus of elasticity and hardness of composites slightly decrease. The addition of modifier into the epoxy polymer provides an increase in heat resistance from 86 to 132–156 °C, also it improves the thermal stability of the composite, which manifests itself in a shift from the initial temperature to higher temperatures (from 200 to 230 °C), while it is noticed furthermore that yield of carbonized Structures was risen from 40 to 54%, providing less release of volatile pyrolysis products into the gas phase, which leads to the decrease in flammability of the epoxy composite and it can be shown in the reduction of its loss in mass while cauterizing in air from 78 to about 4.7% and an increase in the oxygen index from 19 to 28% by volume what transfers the material into class with low flammability. The rational content of diorite and chromite (100 parts by weight of chromite and 50 parts by mass of diorite) is chosen as a filler, which ensures an increase in physical and mechanical characteristics and a reduction in the cost of production: the breaking stress increases by 15–30% and the elastic modulus at bending increases 3.5–4.5 times, the breaking stress increases by 35%, and the tensile modulus by 50–240%, the hardness increases by 68–95%, while the impact strength remains at the level of the unfilled plasticized composite. In addition, it is proved that the addition of both diorite and chromite provides an increase in the thermal and heat resistance of epoxy composites, also lowers combustibility of the epoxy composite: the weight loss at ignition in air is reduced to 1.2–2.2% and the oxygen index rises from 28 to 30–35% by volume, thus the material does not support combustion in air and belongs to the class of hardly flammable. The study was carried out with the financial support of a grant for young scientists of the SSTU named after Gagarin Yu.A. (project SGTU-287).

A rubber-modified epoxy composite with very high toughness and heat resistance

2019 ◽  
Vol 27 (9) ◽  
pp. 582-586 ◽  
Author(s):  
Binghai Li ◽  
Xiaohong Zhang ◽  
Guicun Qi ◽  
Xiang Wang ◽  
Jiangru Zhang ◽  
...  
Keyword(s):  
Impact Strength ◽  
Heat Resistance ◽  
Epoxy Resin ◽  
High Performance ◽  
Epoxy Composite ◽  
High Heat ◽  
High Toughness ◽  
The Impact ◽  
Modified Epoxy ◽  
Very High

A high performance epoxy composite with very high toughness and heat resistance had been designed and prepared. Epoxy resin TDE-85 with an impact strength of 10.2 kJ m−2, a heat distortion temperature (HDT) of 121°C, and a glass transition temperature of 127°C was chosen as the matrix of the composite, while carboxylic nitrile-butadiene elastomeric nanoparticles (CNB-ENPs) coated with triethanolamine on the surface with a diameter of about 100 nm was selected as the modifier. Surprisingly, the rubber-modified epoxy resin exhibited not only very high toughness but also very high heat resistance. The HDT of epoxy resin TDE-85 after modification increased 57°C, reaching 178°C, while the impact strength increased by 107%, increasing to 21.1 kJ m−2. The relationship between the microstructure and performance had been evaluated by transmission electron microscopy, mechanical testing, and dynamic mechanical analysis. The results showed that the CNB-ENP/TDE-85 composite resulted in large interface and a special morphology after modification.

Study of the Impact Viscosity of the Epoxy Composite Modified Technical Carbon

2020 ◽  
Vol 992 ◽  
pp. 285-289
Author(s):  
S.V. Vasiliev ◽  
Y.Y. Fedorov ◽  
A.V. Savvina
Keyword(s):  
Impact Strength ◽  
Carbon Black ◽  
Epoxy Resin ◽  
Epoxy Composite ◽  
Resin Composite ◽  
Filler Concentration ◽  
Technical Carbon ◽  
Epoxy Resin Composite ◽  
The Impact ◽  
Impact Viscosity

This article discusses effect of filler concentration on impact strength of an epoxy resin composite. The optimal ratio of resin and hardener is defined. Research of the effect of the concentration of the filler - carbon black P505 on the impact strength of a composite material based on epoxy resin ED-20 is made. According to the results of the study, it is shown that with an increase of concentration of the filler from P505 carbon black, the toughness decreases. Fractographic studies of the fracture surfaces of composites were also carried out, which indicate that the introduction of a filler leads to a decrease in the surface energy of destruction. Thus, studies of epoxy composite modified with technical carbon grade P505 showed a decrease in impact strength up to 4 times, depending on the increase in the mass fraction of the filler.

scholarly journals Preparation and Properties of Naringin Epoxy/UiO-66 Composites

2021 ◽  
Author(s):  
Yonggang Du ◽  
Gonghui Shi ◽  
Hui Wang ◽  
Ge Zhao ◽  
Wei Li ◽  
...  
Keyword(s):  
Impact Strength ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Glycidyl Ether ◽  
Casting Process ◽  
Curing Agent ◽  
The Novel ◽  
Limiting Oxygen Index ◽  
The Impact

Abstract The novel bio-based epoxy resin based on naringenin was synthesized. The naringenin epoxy/UiO-66 composites were prepared by casting process with UiO-66 as modifier and maleic anhydride as curing agent. The influences of UiO-66 content on mechanical properties, thermal stability and flame retardancy of naringenin epoxy/UiO-66 composites were investigated. The results showed that the impact strength, glass transition temperature and limiting oxygen index of pure naringenin epoxy resin were 2.0 kJ/m2, 96 ℃ and 1.2% higher than that of di-glycidyl ether of bisphenol A (DGEBA), respectively. UiO-66 can significantly improve the impact strength of naringenin epoxy resin while assisting improve its flame retardancy. When UiO-66 content was 4 wt%, the impact strength and limiting oxygen index of the naringenin epoxy/UiO-66 composite were 7.6 kJ/m2 and 24.5%, which were 85.4% and 3.5% higher than that of pure naringin epoxy resin, respectively.

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.

scholarly journals Mechanical Properties of Bio-Composites Based on Epoxy Resin and Nanocellulose Fibres

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3576
Author(s):  
Martyna Roszowska-Jarosz ◽  
Joanna Masiewicz ◽  
Marcin Kostrzewa ◽  
Wojciech Kucharczyk ◽  
Wojciech Żurowski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Raw Materials ◽  
Critical Stress Intensity Factor ◽  
Epoxy Composites ◽  
Chemical Extraction ◽  
Cellulose Pulp ◽  
The Impact ◽  
Unmodified Epoxy

The aim of our research was to investigate the effect of a small nanocellulose (NC) addition on an improvement of the mechanical properties of epoxy composites. A procedure of chemical extraction from pressed lignin was used to obtain nanocellulose fibers. The presence of nanoparticles in the cellulose pulp was confirmed by FTIR/ATR spectra as well as measurement of nanocellulose particle size using a Zetasizer analyzer. Epoxy composites with NC contents from 0.5% to 1.5% w/w were prepared. The obtained composites were subjected to strength tests, such as impact strength (IS) and resistance to three-point bending with a determination of critical stress intensity factor (Kc). The impact strength of nanocellulose composites doubled in comparison to the unmodified epoxy resin (EP 0). Moreover, Kc was increased by approximately 50% and 70% for the 1.5 and 0.5% w/w NC, respectively. The maximum value of stress at break was achieved at 1% NC concentration in EP and it was 15% higher than that for unmodified epoxy resin. The highest value of destruction energy was characterized by the composition with 0.5% NC and corresponds to the increase of 102% in comparison with EP 0. Based on the analysis of the results it was noted that satisfactory improvement of the mechanical properties of the composite was achieved with a very small addition of nanofiller while other research indicates the need to add much more nanocellulose. It is also expected that this kind of use of raw materials will allow increasing the economic efficiency of the nanocomposite preparation process. Moreover, nanocomposites obtained in this way can be applied as elements of machines or as a modified epoxy matrix for sandwich composites, enabling production of the structure material with reduced weight but improved mechanical properties.

scholarly journals Synergetic Effects of Silver Nanowires and Graphene Oxide on Thermal Conductivity of Epoxy Composites

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1264 ◽  
Author(s):  
Li Zhang ◽  
Wenfeng Zhu ◽  
Ying Huang ◽  
Shuhua Qi
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Silver Nanowires ◽  
Phonon Transport ◽  
Epoxy Composites ◽  
Hybrid Fillers ◽  
Interfacial Contact ◽  
The Impact

One-dimensional silver nanowires (AgNWs) and two-dimensional graphene oxide (GO) were combined to construct a three-dimensional network structure. The AgNWs can effectively inhibit stacking of adjacent GO sheets by occupying regions between layers of GO. Moreover, the GO sheets embedded in the gaps of the AgNWs network increase the interfacial contact area between the AgNWs and the epoxy matrix, resulting in the formation of more efficient phonon transport channels. To prepare an epoxy-based thermal conductive composite, hybrid networks were fabricated and added to epoxy resin using a solution mixing method. Significant synergistic effects were observed between the AgNWs and GO sheets. The thermal conductivity of epoxy composites filled with 10 wt.% AgNW/GO hybrids was found to be 1.2 W/mK and the impact strength was 28.85 KJ/m2, which are higher than the corresponding values of composites containing AgNWs or GO sheets alone. Thus, the thermal conductivity and impact strength of the epoxy composites were improved. The additive effects are mainly owing to the improved interfacial contact between the hybrid fillers and the epoxy resin, resulting in a more efficient phonon transport network. The use of hybrid fillers with different structures is a simple and scalable strategy for manufacturing high-performance thermally conductive materials for electronic packaging.

Evaluation of the Aging Behavior of High Density Polyethylene in Thermal Oxidative Environment by Principal Component Analysis

2017 ◽  
Vol 727 ◽  
pp. 447-449 ◽  
Author(s):  
Jun Dai ◽  
Hua Yan ◽  
Jian Jian Yang ◽  
Jun Jun Guo
Keyword(s):  
Principal Component Analysis ◽  
Impact Strength ◽  
High Density Polyethylene ◽  
Tensile Modulus ◽  
Principal Component ◽  
Component Analysis ◽  
High Density ◽  
Aging Behavior ◽  
Data Set ◽  
The Impact

To evaluate the aging behavior of high density polyethylene (HDPE) under an artificial accelerated environment, principal component analysis (PCA) was used to establish a non-dimensional expression Z from a data set of multiple degradation parameters of HDPE. In this study, HDPE samples were exposed to the accelerated thermal oxidative environment for different time intervals up to 64 days. The results showed that the combined evaluating parameter Z was characterized by three-stage changes. The combined evaluating parameter Z increased quickly in the first 16 days of exposure and then leveled off. After 40 days, it began to increase again. Among the 10 degradation parameters, branching degree, carbonyl index and hydroxyl index are strongly associated. The tensile modulus is highly correlated with the impact strength. The tensile strength, tensile modulus and impact strength are negatively correlated with the crystallinity.

scholarly journals An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2205
Author(s):  
Qian Li ◽  
Yujie Li ◽  
Yifan Chen ◽  
Qiang Wu ◽  
Siqun Wang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Decomposition Temperature ◽  
Ease Of Use ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
Low Viscosity ◽  
The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

Preparation and properties of novel sulfonic graphene oxide–epoxy resin nanocomposites by resin transfer molding process

2016 ◽  
Vol 51 (9) ◽  
pp. 1197-1208 ◽  
Author(s):  
Wei Li ◽  
Hongyu Li ◽  
Xinguo Yang ◽  
Wei Feng ◽  
Hongyun Huang
Keyword(s):  
Graphene Oxide ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Curing Temperature ◽  
Flexural Property ◽  
Oxide Content ◽  
Molding Process ◽  
One Pot ◽  
Epoxy Resin Nanocomposites ◽  
The Impact

This paper reported a facile one-pot strategy for fabrication of sulfonic graphene oxide–epoxy resin nanocomposites. The rheological and thermal properties were employed to characterize the viscosity and the curing temperature of epoxy resin. Fourier transform infrared spectra for sulfonic graphene oxide and nanocomposites indicated that the sulfonic graphene oxide contains chemical cross-linking responsible for better interactions with the epoxy resin. The state of dispersion was evaluated at different scales by still picture camera and scanning electron microscopy (SEM). Tensile property tests indicated that the tensile strength and elasticity modulus of sulfonic graphene oxide–epoxy resin nanocomposites decreased slowly with increasing of sulfonic graphene oxide content. The critical flexural property and impact strength of epoxy resin filled with sulfonic graphene oxide nanocomposites were measured. The content, size, and dispersion state of sulfonic graphene oxide were examined. It was found that the content of sulfonic graphene oxide has greater impact on both flexural property and impact strength of nanocomposites compared with other conditions. For instance, the impact strength increased by 113.0% and the flexural strength and modulus increased by 39.3% and 55.7% using 1 wt.% sulfonic graphene oxide as compared to neat epoxy resin.

scholarly journals Effect of Filler Nature on Chemical Resistance and Microhardness of Epoxy Composite Films

2015 ◽  
Vol 16 (3) ◽  
pp. 528-533
Author(s):  
G. Martinyuk ◽  
O. Aksimentyeva ◽  
N. Skoreiko ◽  
V. Zakordonskyi
Keyword(s):  
Mechanical Properties ◽  
Chemical Resistance ◽  
Filler Content ◽  
Epoxy Composite ◽  
Composite Films ◽  
Physical And Mechanical Properties ◽  
Epoxy Composites ◽  
Mineral Filler ◽  
Operating Characteristics ◽  
Mineral Fillers

We investigated the processes of water absorption, chemical stability and microhardness of films of epoxy composites that contained as the polymer matrix the epoxy resin UP-655 and mineral fillers: graphite, mica, aluminum oxide at their content (0 - 30 % mass). It found that introduction of mineral fillers significantly affects on all complex of operating characteristics of the films. Increase of filler content, especially mica, to 20 %, resulting in slower process and reducing the quantity of absorbed moisture by films. In the study of physical and mechanical properties of filled epoxy composites was established that the introduction of mineral filler significantly affects their microhardness, and the nature of the exposure is determined by the type and filler content.

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