scholarly journals Reinforcement of Epoxy Composites with Graphite-Graphene Structures

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. S. Mostovoy ◽  
A. V. Yakovlev

Abstract As a result of the research, the possibility of directional control of the operational properties of epoxy composites by the use of small additives of thermally expanded graphite-graphene structures has been proved. The rational content of the structuring additive in the composition of the epoxy composite (0.05 parts by mass.) was selected, which ensured an increase in the studied complex of physico-mechanical properties. The influence of thermally expanded graphite on the process of structure formation of an epoxy composite has been established. The addition of thermally expanded graphite increases thermal, fire and heat resistance as well as the coefficient of heat-conducting epoxy composite.

2020 ◽  
Vol 25 (4) ◽  
pp. 203-213
Author(s):  
B.H. Abed ◽  
K.J. Jadee ◽  
A.A. Battawi

AbstractThe creep test is one of the important approaches to determining some mechanical properties of composite materials. This study was carried out to investigate the creep behaviour of an epoxy composite material that was reinforced with Y2O3 powder at weight ratios of 2%, 7%, 12%, 17% and 22%. Each volume ratio was subjected to five loads over the range of 1N to5N at a constant temperature of 16 ± 2°C. In this work, creep behaviour, stress and elasticity modulus were studied through experimental and numerical analyses. Results showed that increasing the weight ratio of Y2O3 powder enhanced creep characteristics.


2015 ◽  
Vol 16 (3) ◽  
pp. 528-533
Author(s):  
G. Martinyuk ◽  
O. Aksimentyeva ◽  
N. Skoreiko ◽  
V. Zakordonskyi

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.


RSC Advances ◽  
2015 ◽  
Vol 5 (74) ◽  
pp. 60596-60607 ◽  
Author(s):  
Lulu Pan ◽  
Jianfeng Ban ◽  
Shaorong Lu ◽  
Guoxin Chen ◽  
Jin Yang ◽  
...  

A novel reduced graphene oxide/perylene bisimide-containing hyperbranched polyglycerol was successfully prepared via π–π stacking interactions. The thermal and mechanical properties of the epoxy composite were enhanced significantly.


Author(s):  
A. S. Mostovoi ◽  
A. S. Nurtazina ◽  
Yu. A. Kadykova

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).


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shailendra Singh Chauhan ◽  
Vaibhav Singh ◽  
Gauranshu Saini ◽  
Nitin Kaushik ◽  
Vishal Pandey ◽  
...  

Purpose The growing environmental awareness all through the world has motivated a standard change toward planning and designing better materials having good performance, which are very much suited to the environmental factors. The purpose of this study is to investigate the impact on mechanical, thermal and water absorption properties of sawdust-based composites reinforced by epoxy, and the amount of sawdust in each form. Design/methodology/approach Manufacturing of the sawdust reinforced epoxy composites is the main area of the research for promoting the green composite by having good mechanical properties, biodegradability or many applications. Throughout this research work, the authors emphasize the importance of explaining the methodology for the evaluation of the mechanical and water absorption properties of the sawdust reinforced epoxy composites used by researchers. Findings In this paper, a comprehensive review of the mechanical properties of sawdust reinforced epoxy composite is presented. This study is reported about the use of different Wt.% of sawdust composites prepared by different processes and their mechanical, thermal and water absorption properties. It is studied that after optimum filler percentage, mechanical, thermal properties gradually decrease, but water absorption property increases with Wt.% of sawdust. The changes in the microstructure are studied by using scanning electron microscopy. Originality/value The novelty of this study lies in its use of a systematic approach that offers a perspective on choosing suitable processing parameters for the fabrication of composite materials for persons from both industry and academia. A study of sawdust reinforced epoxy composites guides new researchers in the fabrication and characterization of the materials.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 79 ◽  
Author(s):  
Jeesoo Sim ◽  
Youngjeong Kang ◽  
Byung Joo Kim ◽  
Yong Ho Park ◽  
Young Cheol Lee

In this research, a fly ash/epoxy composite was fabricated using fly ash filler classified as industrial waste. The behavior of its mechanical properties was investigated by changing the volume of fly ash to 10, 30 and 50 vol.%. To determine the influence of particle size on the mechanical properties, we used two different sizes of the fly ash, which were separated by sieving to less than 90 μm and 53 μm. To optimize fabrication conditions, the viscosity of the fly ash/epoxy slurry was measured at various temperatures with different fly ash volume fractions. In terms of mechanical properties, tensile strength increased as the amount of fly ash increased, up to a critical point. On the other hand, the compression strength of the composite increased continuously as the amount of fly ash increased. Finally, the fracture surfaces were characterized and correlated with the mechanical properties.


2020 ◽  
Vol 54 (20) ◽  
pp. 2781-2801 ◽  
Author(s):  
Yousef Saadati ◽  
Gilbert Lebrun ◽  
Jean-Francois Chatelain ◽  
Yves Beauchamp

Using natural fibers as reinforcement in polymer matrix composites necessitates evaluating the latter under different modes of solicitation. This allows extracting its material properties for engineering design and research purposes. The main objective of the study is preparing a consistent set of material properties for unidirectional flax fiber-reinforced epoxy composite with defined composition and basic configuration. These data are prerequisites for growing researches on flax fiber-reinforced epoxy composites, especially for numerical analysis purposes using the finite element method. In this work, partially green unidirectional-flax fiber-reinforced epoxy composites are tested for physical and mechanical properties and studied for their failure modes. Tension, compression, flexion, and shear properties, as well as physical properties like density, specific heat capacity and thermal diffusivity, are evaluated according to ASTM standard test methods. Flax fibers, which are composites by themselves, come in bundles in the composites and demonstrate a complex behavior. Therefore, a fractographic analysis has been conducted to understand the macro and microscale failure mechanisms to correlate them with the material properties. The results are in good agreement with those of the literature, when available, but they mainly show the specific behavior of unidirectional-flax composites subject to different solicitation modes, especially compression and direct shear modes evaluated this way for the first time for unidirectional-flax fiber-reinforced epoxy composite. They cover most of the data required for engineering design and numerical analysis by methods like finite element method, particularly for simulating the machining process of flax fiber-reinforced epoxy composite in the ongoing works.


Sign in / Sign up

Export Citation Format

Share Document