Influence of Different Nano-Structured Fillers on the Performance of Epoxy Nanocomposites

2020 ◽  
Vol 29 ◽  
pp. 51-60
Author(s):  
Amr Osman ◽  
Abdelmoty Elhakeem ◽  
Saleh Kaytbay ◽  
Abdalla Ahmed

Nowadays, multi-functional materials are strongly needed to meet the requirements of next-generation electronic devices. In this work, two different nanostructured fillers, reduced graphene oxide (RGO) and nanoalumina, were chosen to study their effect on the thermal, electrical and mechanical properties of the prepared epoxy composites at different loadings (0.5 to 2 wt%). RGO was firstly prepared and characterized by XRD, Raman spectroscopy and TEM confirming its production. The results revealed that RGO showed excellent adhesion with the polymer. Whilst, alumina aggregated and debonded from the matrix, as confirmed by SEM images. Hence, at only 2 wt%, RGO/epoxy composites exhibited the highest thermal conductivity (0.391 W/m-K), which was 1.96 times higher than the neat epoxy. Whereas, the alumina/epoxy composites showed lower increment at the same loading (0.206 W/m-K). However, at 2 wt% RGO, electrical percolation networks had been formed across the matrix (DC conductivity = 2×10-7 S/cm). While, epoxy filled with alumina remained insulative at any loading (~ 10-12 S/cm at 100 Hz). Besides, the tensile strength of the composites was improved by 75% and 37% when filled with 0.5 wt% RGO and alumina, respectively. These results are very useful for preparing multi-functional polymeric materials, which are critically required for packaging industries.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yufei Chen ◽  
Hui Zhao ◽  
Yulong Liu ◽  
Hongyue CHU

Purpose Bismaleimide (BMI) is a kind of thermosetting resin and its application is usually limited by low toughness. In this paper, two kinds of reinforcement intercalator amino-terminated polyoxypropylene (POP) and octadecyl trimethyl ammonium chloride (OTAC) were designed and synthesized to toughen BMI resin and the toughening effect was compared and analyzed. The purpose of this paper is to toughen BMI resin and analyze the toughening effect of two reinforcements intercalator amino-terminated polyoxypropylene (POP) and octadecyl trimethyl ammonium chloride (OTAC). Design/methodology/approach Sodium-based montmorillonite (Na-MMT) was modified by POP and OTAC, and the ion-exchange reaction obtained organic montmorillonite (POP-MMT and OTAC-MMT). The polymer matrix (MBAE) was synthesized, in which 4,4’-diamino diphenyl methane BMI was used as the monomer and 3,3’-diallyl bisphenol A and bisphenol A diallyl ether were used as active diluents. And then, POP-MMT/MBAE and OTAC-MMT/MBAE composites were prepared using MBAE as matrix and POP-MMT or OTAC-MMT as reinforcement. The Fourier-transform infrared, X-ray diffraction and scanning electron microscope (SEM) of the filler and microstructure and mechanical properties of the composite were characterized to the better reinforcement. Findings POP-MMT and OTAC-MMT enhanced BMI-cured products’ toughness by generating microcracks in the polymer to absorb more fracture energy. Meanwhile, POP-MMT and OTAC-MMT were the main stress components and the enhancement of the interface interaction was beneficial to transfer the external force from the matrix to the reinforcement and improved the mechanical properties of the composite. Furthermore, with the intercalation rate increasing, the compatibility of the two phases was increased and the performance of MBAE was also elevated. Research limitations/implications BMI is generally used as aerospace structural materials, functional materials, impregnating paint and other fields. However, high crosslinking density leads to moulding material’s brittleness and limits a wider range of applications. Therefore, it has become an urgent priority to explore and improve the mechanical properties of BMI resin. Originality/value POP and OTAC have successfully intercalated Na-MMT layers to get POP-MMT and OTAC-MMT, and the interplanar crystal spacing and the intercalation rate were calculated, respectively. The results were corresponding with the SEM images of POP-MMT and OTAC-MMT. After that, the morphology of composites illustrated the compatibility was related to the intercalation rate. According to the mechanism of modified MMT toughening epoxy resin, when they were dispersed uniformly in the matrix, the composite’s mechanical properties had been significantly improved. Additionally, OTAC-MMT with a higher intercalation rate had better compatibility and interfacial force with the matrix, so that the mechanical properties of OTAC-MMT/MBAE were the best.


2013 ◽  
Vol 738 ◽  
pp. 56-60 ◽  
Author(s):  
Yue E Liu ◽  
Cheng En He ◽  
Ren Gui Peng ◽  
Wei Tang ◽  
Ying Kui Yang

Graphene nanosheets were prepared by chemical reduction of the exfoliated graphite oxide using sodium borohydride (NaBH4). The graphene/epoxy composites were separately fabricated in the absence or presence of imidazolium-based ionic liquids, and their dynamic thermomechanical and tensile properties were studied. TEM examinations show that graphene sheets are well dispersed in the epoxy resin and have strong interface adhesion with the matrix due to the π-π and/or cation-π interactions between graphene and imidazolium ions. The composite fabricated by assistance of ionic liquids shows larger increases in Youngs modulus, tensile strength, storage modulus and glass transition temperature compared to the composite without using ionic liquids. This work provides a method for the fabrication of multifunctional graphene-based polymer composites.


2022 ◽  
Vol 30 ◽  
pp. 096739112110609
Author(s):  
Atik Mubarak Kazi ◽  
Ramasastry DVA

The influence of fibre orientation on physical, mechanical and dynamic mechanical properties of Hibiscus sabdariffa fibre composites has been studied. The composites with longitudinal (0°), transverse (90°) and inclined (45°) fibre orientation were prepared using the hand layup technique. ASTM standards were used for characterization of continuous Hibiscus sabdariffa fibre composites. The composite with longitudinally placed fibres yields improved mechanical characteristics. The addition of longitudinal (0°) oriented continuous Hibiscus sabdariffa fibres to the epoxy enhances tensile strength by 460%, flexural strength by 160% and impact strength by 603% compared to neat epoxy. The longitudinal (0°) fibre oriented composite offers higher resistance to water absorption and thickness swelling compared to other types of composites. All continuous Hibiscus sabdariffa fibre epoxy composites possess an improved storage modulus than the neat epoxy resin. The glass transition temperature of continuous Hibiscus sabdariffa fibre composites is 8%–31% lower than that of neat epoxy. Scanning electron microscopy (SEM) images confirm the existence of voids in the matrix, fibre pullout and crack propagation near the fibre bundle, which indicates the stress transfer between fibre and matrix is non-uniform.


2019 ◽  
Vol 130 ◽  
pp. 01040 ◽  
Author(s):  
Yuniar Ratna Pratiwi ◽  
Indah Widiastuti ◽  
Budi Harjanto

The aim of this article is to evaluate water absorption in bamboo fiber composites. Bamboo is hydrophilic, means that it easily absorbs water. In this study the bamboo fiber-based composites were developed using hand lay up method, with epoxy resin as the matrix constituent. Water absorption characteristics of specimens of bamboo composite and epoxy were determined from water immersion tests at several temperatures. Gravimetric analysis was performed to determine the moisure absorbed as a function of time at two different temperatures: 25 ºC and 50 C. The diffusivity of water in an epoxy bamboo composite was determined after reaching saturation point. During room temperature soaking, epoxy specimen showed the characteristic of Fickian behavior. Similar immersion tests on bamboo-epoxy composites followed nonfickian behavior. Changes in the mechanical properties of material due to water absorption were evaluated from tensile testing on materials with varied water content. It was found that the waterabsorption in all samples reduced the tensile properties. The degradation of tensile properties was greater with an increasing temperature of immersion. The results of this study emphasize the importance ofconsidering deterioration of mechanical properties in the bamboo epoxy composites during their application in water and possibly in humid environment.


2017 ◽  
Vol 63 ◽  
pp. 1-11 ◽  
Author(s):  
Suman Chhetri ◽  
Nitai Chandra Adak ◽  
Pranab Samanta ◽  
Naresh Chandra Murmu ◽  
Tapas Kuila

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.


2020 ◽  
Vol 70 (2) ◽  
pp. 167-180
Author(s):  
Vennapusa Vijaya Bhaskar ◽  
Kolla Srinivas ◽  
Devireddy Siva Bhaskara Rao

AbstractThe present work addresses the physical and mechanical properties of banana and palmyra fiber reinforced epoxy composites with the aim of study on the effect of weight ratio and fiber percentage. The banana and palmyra fibers were arranged with different weight ratios (1:1, 1:3, and 3:1) and then mixed with the epoxy matrix by hand lay-up technique to prepare the hybrid composites with various fiber percentages (10%, 20%, 30% and 40%). The properties are measured by testing its density, water absorption, tensile strength, impact strength, hardness and flexural strength and compared. From the results, it was indicated that addition of banana and palmyra fiber in to the matrix material up to 30% by fiber percentage results in increasing the mechanical properties and slightly variation with weight ratios. Interfacial analysis of the hybrid composites were also observed by using scanning electron microscope (SEM) to study the internal failures and micro structure of the tested specimen.


2019 ◽  
Vol 8 (4) ◽  
pp. 6972-6977

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.


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