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Corrosion not only causes a lot of economic losses, but possibly threatens personal safety. The superhydrophobic polyaniline composite anti-corrosion coating (SPANC) has closely received attention ...

A robust superhydrophobic perfluoropolysiloxane and self-doped polyaniline/epoxy resin composite coating (EPAN-RA-POS) was prepared. The structure is composed of the internal self-doped polyaniline...

The behavior of electrical conductivity during the curing of composites based on epoxy resin doped with functionalized single-walled carbon nanotubes (SWNTs) with the application of constant and al...

In the present work, chemically treated kenaf fibre (10, 20 and 30 wt. %) reinforced epoxy resin composite formulations were fabricated using hand lay-up technique. The prepared composites were mechanically characterized using Taguchi L27experimental design to examine the influence of varying kenaf fibre wt. %, NaOH concentration % for chemical treatment, and fibre immersion duration. The grey-fuzzy optimization approach was utilized for optimizing prepared formulations mechanical properties such as tensile strength, impact strength and flexural strength. Further, analysis of variance (ANOVA) tests and response graphs were utilized for delivering model significance and determining the percentage contribution of input variables. The NaOH concentration % was found to be most significant parameter followed by kenaf wt. % in providing best mechanical properties of chemically treated kenaf fibre reinforced epoxy composites.

Purpose Recently, composites have concerned considerable importance as a potential operational material. Lots of work have been carried out to enhance the mechanical properties of composites. The main aim of this paper is to develop bamboo mat as reinforcing material with bagasse fiber as filler using epoxy resin matrix composite. Design/methodology/approach In this research, the effect of fiber surface treatments on mechanical properties of epoxy resin composite with bagasse as filler has been developed and investigated. The extracted bamboo fibers were treated with NaOH to improve the surface roughness fiber. Using treated and untreated bamboo fiber handwoven mat has been produced to be used as reinforcement and bagasse fiber has been converted into powder to be filled as filler. Composite material is fabricated using bamboo fiber and bagasse fiber as filler with epoxy resin as a matrix using hand layup technique. Findings Then, tensile, flexural and compressive strength and water absorption tests were conducted on sodium hydroxide treated and untreated fiber composites. The test results comparing with and without alkali treated composites show that there was significant change in their strength and water absorption properties on alkali treated fiber. Originality/value This study is an original research paper.

A subject of continuous discussion in the field of underwater archaeology is how to safely extract fragile waterlogged artifacts while maintaining their best condition. In this study, lacquerware with fragile wooden body was simulated and extracted, using a triple-package reinforcement technique. Using veratraldehyde as a temporary consolidant, SH-MWCNTs@PU sponge/epoxy resin composite materials as free-form reinforced layers, and double-sided self-adhesive bandages wrapped around the outer layer, the safe underwater extraction and the layer-by-layer removal of the simulated artifacts were studied. The method maximized the preservation of the artifacts’ state and information and minimized their damage during removal and transport. This method can be used as a technique for the extraction of fragile artifacts from underwater archaeological excavation sites.

This study reports the evaluation of the anticorrosive performance of polymer epoxy resin, namely, Diglycidyl ether 4, 4’-dihydroxydiphenylsulfone (DGEDDS) and its polymer composite reinforced with Titanium Dioxide (TiO2), for carbon steel (CS) corrosion, in 3% wt. NaCl, using experimental analyses. Thermal, electrochemical and morphological techniques were used to demonstrate the anticorrosive effectiveness of the standard epoxy resin (MP1) and its TiO2 composite (MP2). The effect of UV irradiation (for 2000 h), on the effectiveness of MP1 and its TiO2 composite (MP2), showed that TiO2 presence appreciably enhanced the protection efficiency effect of MP1.

The quartz fiber-reinforced epoxy resin-based composites (QFRECs) were fabricated by resin transfer molding (RTM), and then the effect of laser ablation on the structure and dielectric properties of the prepared composite was investigated. The FTIR, XRD, and SEM analyses show that the thermal decomposition, pyrolysis, carbonization, graphitization, and ablation occurred on the surface of the epoxy resin under laser irradiation. The in situ produced carbon endows the QFREC with an improved dielectric constant, which increases maximally from 3.3 to 4.5 in the range of 7–17 GHz under the energy intensity of 226 W·cm−2. Compared with short-time irradiation (5 s), long-time irradiation (10 s) exhibits a greater impact on the dielectric constant due to the formation of crystal graphite at prolonged high temperature. Meanwhile, the rough and deep pits are inclined to form onthe surface of the long-time irradiative composite. These findings provide guidance for the practical application of QFREC as wave-transmitting materials.

The congress gross is a severe weed of wastelands, pasture and agricultural fields in the world. It is a highly pliable weed and able to grow anywhere, occupy all kinds of pasture lands and cause considerable losses in the field of agriculture. In this paper, the properties of mechanical such as tensile, flexural and Impact strength of Congress gross fiber inserted composite are tested according to ASTM-D638, ASTM-D790, and D-256 standards. The paper is aimed at developing the Congress gross fiber reinforced epoxy resin composite on different fiber volume ratios of 5%, 10%, 15%, and 20%. For different volume ratios of Congress gross fiber and epoxy resin, an average of three specimens will be considered. Congress's gross fiber composite is prepared by hand layup process only. Proper precaution should be taken while extractions of fiber. The weighing machine platform is prepared using results obtained. The limitation of the platform is 150 kg.

The intensifying global distress towards the environmental problems and however, the demand for more versatile polymer-based materials has raised concerns about polymer composites containing natural organic fillers, i.e. fillers derived from renewable sources and biodegradable. The composites, which are often referred to as “green,” can be used in a variety of ways. Green composites are commonly listed as having possible applications in the automotive and construction industries, but an analysis of these applications shows that they are frequently an inappropriate fit for green composites' specific material properties. A concise summary of green composites is given, along with graphical comparisons of their relative benefits. In the present study flexural stress is calculated by using CATIA V5, AGMA and ANSYS. Designing a product is an important industrial activity that affects the quality of product, so because of this three dimensional objects is created, analysed and comparison among the three materials according to ASTM D 790 standard using modelling software CATIA V5. Coconut fiber reinforced with epoxy resin composite will have more life and durable because of its less deformation and high stress bearing capacity.

To research the axial compression properties of unidirectional carbon fiber reinforced epoxy resin composite (UCFREP), the compression experiments at different strain rates were carried out by using the MTS universal electronic testing machine and the equipment of split Hopkinson pressure bar (SHPB). Furthermore, the finite element analysis (FEA) was also used to study the compression properties of UCFREP with different conditions. The true stress-strain curves in quasi-static and dynamic compression were obtained, and the relationship between yield limit and strain rate was coupled. The microstructure of the failure area was observed by scanning electron microscope (SEM). A formula for predicting compression strength of combined buckling under the quasi-static condition was presented. The application range of Chang-Chang failure criterion was discussed by FEA, and the compression failure of UCFREP with different fiber directions was predicted. The results show that UCFREP has the obvious strain rate effect, the mechanical properties at dynamic compression are nonlinear. Shear is the main compression failure mode, which includes the shear cracking of matrix between fibers and the shear buckling of fiber. The direction of the fiber is the main factor that causes the shear cracking, such as the shear cracking shows the feature of 45° when the direction of the fiber is 45°. As a conclusion, increasing the shear strength of matrix and fiber will be a way to increase the compression strength of UCFREP. This paper could be used as a reference to develop the new constitutive model, especially considering the nonlinear effect.

The aim of this study was to produce carbon nanotubes (CNTs)/polymer composite fibers by wet spinning without any solvent. The functionalized multiwalled-carbon nanotubes (F-MWNTs)/epoxy resin was synthesized by in situ polymerization method. Epoxy resin, F-MWNTs, and curing agent were mixed and injected by a syringe pump. The effects of operating parameters including the percentage of CNTs and the extrusion velocity of the syringe pump on the dispersion and alignment of F-MWNTs in the cross-section of F-MWNTs/polymer composite fibers were investigated. The composite fibers were characterized by tensile strength analysis, scanning electron microscopy (SEM), and electrical conductivity analysis. The experimental results showed that a decrease (30 ml/h to 15 ml/h) in extrusion velocity increased the electrical conductivity of composite fibers by more than 3%. This behavior was attributed to the higher alignment of F-MWNTs and improved conducting pathways along the composite fiber axis, as observed by SEM. In addition, by reducing extrusion velocity (30 ml/h to 15 ml/h), the tensile strength of composite fibers was enhanced just over twofold due to the better arrangement of CNTs which can be attributed to the further retention time of composite fibers and the pressure of the walled-needle. Moreover, the higher the processing time of spinning, the lower electrical conductivity of the fibers is which might be due to the higher coagulation of fibers.

To study the ageing characteristics of epoxy resin composite insulation in dry-type transformers in high-temperature environments, glass fibre-reinforced epoxy resin samples were placed in a hot air ageing environment at 130°C for testing. Dielectric properties, partial discharge (PD), microscopic morphology, three-dimensional morphology and Fourier transform infrared spectroscopy of aged samples were periodically tested. The results show that during the ageing process, the change in the surface morphology of the sample leads to an overall upward trend in surface roughness, and the older the sample, the faster the surface roughness increases; changes in the surface morphology and three-dimensional morphology of the material constitute the basis for judging the condition of the insulating surface and the state of ageing development. Microcracks are the direct cause of debonding of glass fibres and epoxy matrix. Degradation of the sample during the ageing process generates many free radicals, which enhances the polarisation ability of the sample and increases both the dielectric constant and the dielectric loss factor. The real part of the complex dielectric constant is more sensitive to the ageing response of the sample. The older the sample, the greater the effect on the results of the dielectric spectrum test. Since the aged sample generates more hot electrons during the PD process and makes it easier to inject electrons into the material, the PD of the sample is rendered more intense by thermal ageing. There is a significant difference between the degradation mechanism of the thermal ageing and PD. The samples subjected to PD after thermal ageing produce new groups, and the degradation of the samples is more severe than that caused by thermal ageing, or PD, alone.

Carbon fiber epoxy resin composite and polyimide material are likely to be applied to pulley-guideway system of the new satellite antenna. Their tribological properties have effects on the motion characteristics of the pulley-guideway system. To master the tribological properties of carbon fiber epoxy resin composite and polyimide material, this paper carries out tests of tribological properties and wear behavior of carbon fiber epoxy resin composite and polyimide material at 130°C and 30°C. Carbon fiber epoxy resin composite is used as the grinding specimen and polyimide material is used as the counter-grinding specimen. Tribological properties of this material pairs is studied under diverse linear velocity and external loads. The results show that friction coefficient of this material pairs is stable under different conditions, especially at 30°C. Meanwhile, wear behavior of this material pairs is mainly affected by ploughing of surface roughness at low temperature, while by surface micro-spalling at high temperature.

In this study, a bi-directional corrugated lattice sandwich structure was fabricated from jute fibers and epoxy resin. Die casting was used to prepare the core struts and face sheets and two fiber composites were designed to produce structural struts. The configuration and the relative density of the core layer were altered. In addition, the three-point bending properties of each configuration were investigated to explore the various modes of failure, destruction processes, and mechanical properties. Results of the experiments show that failure mainly occurs via three modes: face sheet crushing, face sheet wrinkling, and core member crushing. Moreover, the failure mode is related to the strength of the core struts. Theoretical calculations and finite element analysis were carried out, and the simulation results were in good agreement with experimental results, the relative errors of displacement and load are all within 20 %. In conclusion, the proposed sandwich beam configuration composed of jute fibers could be highly useful for enhancing engineering structurer owing to the simple fabrication process, moreover, the materials are environmentally friendly and inexpensive.

Microcrystalline graphite (MG) was used as raw material and oxidated by Hummers method. And further the graphene oxide (GO) was obtained by ultrasonic stripping. The TP modified graphene (TPG) was prepared by the surface grafting of pure natural green tea extract tea polyphenols (TP) on the surface of GO. Finally, the TPG/epoxy resin composite was prepared by solution blending and heat-curing moulding method.The characterization of structure and properties of TPG was analyzed by X ray diffraction pattern (XRD), infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and X ray photoelectron spectroscopy (XPS). A universal material testing machine was used to test the mechanical properties of epoxy resin composites with different addition of TPG. Field emission scanning electron microscopy (SEM) was used to observe the tensile-sectional morphology of the composites. The thermal stability of the composites was investigated by thermogravimetry and thermal dilatometer. The experimental results showed that the TP molecule was successfully grafted on the oxygen-containing functional groups of the GO surface through the phenolic hydroxyl group.When the addition of TPG was 1.0 wt%, the decomposition temperature of the epoxy resin was increased by 22.2 °C,and the surface resistivity decreased from 1.35×1014 Ω·m to 1.7×109 Ω·m. When the added amount of TPG was 0.5 wt%, the tensile strength of composites was increased by 13.5% reaching 59.85 MPa.

Glass fiber reinforced polymer matrix composites have enticed the researchers since last few decades, due to their excellent mechanical properties and wear resistance behaviour. In this paper woven roving E-glass fiber reinforced epoxy resin composite was prepared by hand lay-up method, followed by curing at 140 °C for 6 h. Density, porosity and different mechanical properties, such as hardness, tensile strength and impact strength were evaluated experimentally, and the test results were compared and validated with the experimental results of open literature. Three-body dry abrasion behaviour of the composite sample was also investigated.

Noise is an unwanted sound; requires reduction and control through the use of absorptive materials. This is imperative due to the adverse effect noise poses to human health, knowledge dissemination, and tranquility which is increasing daily due to industrialization and heightened allied activities. The use of natural and synthetic reinforced composites in noise pollution control is an emerging area of research. This study aims to develop and characterize fly ash nanoparticles reinforced epoxy resin composite for acoustic applications. Samples were prepared with fly ash nanoparticles reinforcement at 5%, 10%, 15%, 20%, and 25% and investigation of noise reduction coefficient (NRC), porosity and mechanical properties (hardness, impact, flexural strength) of samples were done. Cenospheres were obtained when fly ash particles were characterized separately with the aid of sieve analysis and x-ray fluorescence analysis. The cenospheres are hollow spherical and lightweight, inertfiller material. Correlation between porosity of the samples and their sound absorption properties was observed and showed that as porosity increased, the NRC values increased and as the porosity decreased the NRC values decreased. It was also observed that heat of polymerization, fly ash nanoparticles structure and air bubbles during sample preparation (mixing) influenced the porosity values which in turn influenced the NRC values of the composite. There was also a steady decrease in mechanical properties, as reinforcements were added (5%, 10%, 15%, 20%, and 25%), this was attributed to the high surface areas and shape of reinforcement added.

Preparation of phase change materials with higher heat resistance is of great significance for their popularization and application. In this study, based on phase-change microcapsules (micro-PCMs) with epoxy resin as the capsule shell, microcapsules were compounded with different types of epoxy resins to prepare micro-PCMs and epoxy resin composite phase change materials (CPCMs). The results show that by changing the micro-PCMs content in the CPCM, the phase change enthalpy of the CPCM can be flexibly adjusted within the range of 32.41–50.75 J/g. When the Micro-PCMs content was 40%, the 5% weight loss temperature of the CPCM with N, N, N', N'-tetrakis(glycidyl)-1,3-cyclohexanedi(methanamine) (TGCM) was 228.7 ℃. And after heat treatment at 160 ℃ for 30 min, the enthalpy reduction was less than 5%. With the same micro-PCM content, the heat resistance and mechanical properties of the CPCM with TGCM as the matrix are better than with hydrogenated epoxy resin (HBPA).

Herein, the effect of multilayer core–shell-structured Zn/ZnO/Al2O3 particles on thermal conductivity and dielectric properties of epoxy composites was investigated. The core–shell-structured Zn/ZnO particles were obtained by a simple calcination method, and the multilayer core–shell-structured Zn/ZnO/Al2O3 particles were prepared using hydrolysis process. The Zn/ZnO/Al2O3/epoxy composites were fabricated, and atomic force microscopy (AFM) images showed that the fillers were well distributed in epoxy matrix. Thermal conductivity of Zn/ZnO/Al2O3/epoxy composites increased 178% by adding 12.0 wt% of Zn/ZnO/Al2O3 particles. The dielectric constant of composites increased obviously with the increased content of Zn/ZnO/Al2O3 particles, while the dielectric loss is still low. These results illustrate that the combination of the thermal and dielectric properties tuned by multilayer core–shell particles gives potential application in extended domains for epoxy composites.

In this paper, the SEM image of epoxy resin composite material section was analyzed by the image recognition technology. The number of the textures and spots of the SEM image were found and calculated. By coupling the two data, the influencing factors of the impact strength of epoxy resin composites were judged quickly. This method is more helpful to obtain the section image information in a short time and contrast the impact strength of composite materials more effectively.

A composite material is obtained by combining two or more different materials to achieve a superior quality of characteristics than its constituents. Composite materials are widely accepted and are in use across different engineering applications, viz., aerospace, marine, defense, and automobiles. Fiber-reinforced materials are widely used in engineering industries because of their superior performance and tailor-made properties. The carbon fiber orientation plays a significant role in the mechanical properties of the obtained composite, particularly in tensile properties. In this paper, the orientation of carbon fiber in the composite (prepared using epoxy resin) is investigated under tensile loading. The analysis reveals that the experimental studies characterize the type of failure occurs under tensile loading, which is directly influenced by fiber orientation in a composite laminate.

Basin-type insulators are made by epoxy resin composite materials. Curing defects are easily formed in basin-type insulators, and degrade their insulating performances. High curing exothermic rates of epoxy resin composite materials have deemed as the main cause of curing defects formation. In this study, methyl tetrahydrophthalic anhydride (Me-THPA) was used to extend the molecular chain of liquid epoxy resin to prepare epoxy resin composite materials with low curing exothermic rates. Curing exothermic properties, molecular weight distribution, curing stress, microstructures, and surface flashover characteristics of the composite materials were investigated. The results showed that chain-extended epoxy resin had low curing exothermic rates. The curing stress of the chain-extended epoxy resin composite materials was small. The curing defects forming in the composite materials were inhibited. Negative DC surface flashover characteristics of these composite materials were improved. Furthermore, variation of functional groups of the composite materials was studied before and after surface flashover tests. Results showed that the content of carbon–oxygen single bonds (–C–O) in the chain-extended epoxy resin composite materials was observed to decrease. The –C–O bonds also affect the voltage withstand capability of the epoxy resin composite materials.

In this article, the pre-oxidized fiber felt composite material was firstly prepared by a mold press process, and the pre-oxidized fiber and resin were used as the reinforcing material and ...