Improvements in mechanical properties of a carbon fiber epoxy composite using nanotube science and technology (original) (raw)

A strategy for improving mechanical properties of a fiber reinforced epoxy composite using functionalized carbon nanotubes

Carbon fiber reinforced epoxy composite laminates are studied for improvements in quasi static strength and stiffness and tension-tension fatigue cycling at stress-ratio (R-ratio) = +0.1 through strategically incorporating amine functionalized single wall carbon nanotubes (a-SWCNTs) at the fiber/fabric-matrix interfaces over the laminate cross-section. In a comparison to composite laminate material without carbon nanotube reinforcements there are modest improvements in the mechanical properties of strength and stiffness; but, a potentially significant increase is demonstrated for the long-term fatigue life of these functionalized nanotube reinforced composite materials. These results are compared with previous research on the cyclic life of this carbon fiber epoxy composite laminate system reinforced similarly with side wall fluorine functionalized industrial grade carbon nanotubes. Optical and scanning electron microscopy and Raman spectrometry are used to confirm the effectiveness of this strategy for the improvements in strength, stiffness and fatigue life of composite laminate materials using functionalized carbon nanotubes.

Enhancement of mechanical performance of epoxy/carbon fiber laminate composites using single-walled carbon nanotubes

Composites Science and Technology, 2011

Carbon nanotubes (CNT) in their various forms have great potential for use in the development of multifunctional multiscale laminated composites due to their unique geometry and properties. Recent advancements in the development of CNT hierarchical composites have mostly focused on multi-walled carbon nanotubes (MWCNT). In this work, single-walled carbon nanotubes (SWCNT) were used to develop nano-modified carbon fiber/epoxy laminates. A functionalization technique based on reduced SWCNT was employed to improve dispersion and epoxy resin-nanotube interaction. A commercial prepregging unit was then used to impregnate unidirectional carbon fiber tape with a modified epoxy system containing 0.1 wt% functionalized SWCNT. Impact and compression-after-impact (CAI) tests, Mode I interlaminar fracture toughness and Mode II interlaminar fracture toughness tests were performed on laminates with and without SWCNT. It was found that incorporation of 0.1 wt% of SWCNT resulted in a 5% reduction of the area of impact damage, a 3.5% increase in CAI strength, a 13% increase in Mode I fracture toughness, and 28% increase in Mode II interlaminar fracture toughness. A comparison between the results of this work and literature results on MWCNT-modified laminated composites suggests that SWCNT, at similar loadings, are more effective in enhancing the mechanical performance of traditional laminated composites.

Modification of the surface of carbon fibers with multi-walled carbon nanotubes and its effect on mechanical characteristics of composites with epoxy resin

Russian Journal of Applied Chemistry, 2016

Effect of the catalyst composition on the structure of nanotubes layers obtained on the surface of carbon nanofi bers was studied. We found the preliminary functionalization of the surface of carbon fi bers to affect the coating uniformity and the thickness of synthesized nanotube layer. We determined the optimal surface concentration of the catalyst (Fe-Co) which provides uniform layer of nanotubes on the surface of carbon fi bers. The effect of modifi cation of the surface of carbon fi bers with multi-walled carbon nanotubes on the mechanical properties of carbon fi ber-epoxy resin composites was examined. The modifi cation of the carbon fi bers with multi-walled carbon nanotubes were shown to increase the fl exural modulus and the fl exural strength.

Characterization of Carbon Fiber Reinforced Epoxy Composites Modified with Nanoclay and Carbon Nanotubes

Procedia Engineering, 2015

Fiber reinforced polymer composites show significantly superior performance over many traditional metallic materials because of their superior strength to weight ratio and higher stiffness. Enhancement of properties of FRP composites can be possible by the modification of matrix properties. Significant development in the use of nanoparticles for modification of epoxy matrix has led to improved mechanical properties of the FRP composites. In this study, carbon fiber reinforced epoxy composites were modified with 2 wt.% Montmorillonite nanoclay and 0.3 wt.% multi-walled carbon nanotubes (MWCNTs). 3 point bending test, Dynamic Mechanical Analysis (DMA) and low velocity impact test (LVI) were conducted for characterizing modified samples. Results obtained from these experiments were compared with unmodified carbon/epoxy composites. Reinforcement with nanoparticles was found to significantly improve the mechanical and thermo-mechanical properties of carbon fiber reinforced polymer (CFRP) composites.

Influence of Multi-Walled Carbon Nanotubes on the Thermal and Mechanical Behavior of Carbon/Epoxy Composites (Preprint)

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Mechanical behaviour of a Carbon Fabric-Reinforced Epoxy Composite with Carbon Nanotubes

Carbon fibre–reinforced epoxy composites are used in aerospace for aircraft primary constructions where reliability is the main concern. The aircraft safety depends not only on mechanical properties but also on the electrical conductivity that needs to be high to protect an airplane against lightning strikes. This article describes the mechanical test results obtained during the first part of the IASS European project. The mechanical properties were decreased no more then by 10% by adding Carbon nanotubes (CNTs) and Glycidyl POSS (GPOSS). If we consider the benefit of CNTs as nanofiller to increase the electrical conductivity and the GPOSS as component to increase the flame resistance of the resin, the decrease seems to be not significant.

Fabrication and evaluation of carbon nano fiber filled carbon/epoxy composite

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006

In the present investigation, carbon nano fibers (CNFs) were infused into part-A of SC-15 epoxy (diglycidylether of bisphenol A) through a high intensity ultrasonic liquid processor and then mixed with part-B of SC-15 (cycloaliphatic amine hardener) using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. DMA, TGA, and tensile tests were performed on unfilled, 1, 2, and 3 wt.% CNF filled SC-15 epoxy to identify the loading effect on thermal and mechanical properties of the matrix. The tensile results indicated that 2.0 wt.% CNF/epoxy resin showed the highest improvement in strength as compared to the neat systems. After that, the nanophased matrix with 2 wt.% CNF was then utilized in a vacuum assisted resin transfer molding (VARTM) set up with satin weave carbon preforms to fabricate laminated composites. The resulting structural composites have been tested under flexural loads to evaluate mechanical properties, and 22.3% improvement in flexural strength was observed in nanocomposite. Based on the experimental result, a linear damage model has been combined with the Weibull distribution function to establish a constitutive equation for neat and nanophased carbon/epoxy.

Effect of Carbon Nanotube on Thermo-Mechanical Properties of Glass Fiber/Epoxy Laminated Nanocomposites

Nanocomposites has emerged, penetrated and conquered the market over the past years due to its wide range of applications. The processing of nanocomposites is one of the fastest growing areas in materials research due to the potential of significantly changing material properties even at low nanomaterial concentrations. The thermo-mechanical behaviors were investigated experimentally for two systems of glass fiber reinforced epoxy composites: with carbon nanotubes (CNTs) and without CNTs. An experimental campaign which involves 4 layers laminates were conducted in this study. A manufacturing process using hand lay-up technique followed by hot pressing techniques was used to produce glass fiber-reinforced laminates with the epoxy matrix and with the CNT based epoxy matrix. The surface characterization and thermo-mechanical behavior of the glass fiber-epoxy system and glass fiber-CNT/epoxy system was characterized through Scanning Electron Microscopy (SEM) and Dynamic Mechanical Analysis (DMA).

Fabrication and characterization of carbon/epoxy composites mixed with multi-walled carbon nanotubes

Materials Science and Engineering: A, 2008

In this study, a high-intensity ultrasonic liquid processor was used to obtain a homogeneous mixture of epoxy resin and multi-walled carbon nanotubes (CNTs). The CNTs were infused into epon 862 epoxy resin through sonic cavitation and then mixed with W curing agent using a high-speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. Flexural tests and fracture toughness tests were performed on unfilled and CNT-filled epoxy to identify the effect of adding CNTs on the mechanical properties of epoxy. The highest improvement in strength and fracture toughness was obtained with 0.3 wt% CNT loading. The nanophased matrix filled with 0.3 wt% CNT was then used with weave carbon fabric in a vacuum-assisted resin transfer molding (VARTM) set up to fabricate composite panels. Flexural tests, thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) were performed to evaluate the effectiveness of adding CNTs on the mechanical and thermal properties of the composite. The glass transition temperature, decomposition temperature, and flexural strengths were improved by infusing CNTs. Based on the experimental result, a linear damage model has been combined with the Weibull distribution function to establish a constitutive equation for neat and nanophased carbon/epoxy. Simulated result show that that infusing CNTs increases Weiubll scale parameter, but decrease Weibull shape parameter.

Interface modification of carbon fiber reinforced epoxy composite by hydroxyl/carboxyl functionalized carbon nanotube

Materials Today: Proceedings, 2020

Carbon fiber reinforced epoxy (CE) composites are already in extensive use as structural materials in aerospace and marine applications owing to their inherent high specific strength. This study proposes to further improve their mechanical properties by incorporating Hydroxyl/Carboxyl functionalized carbon nanotube (CNT-OH/CNT-COOH) nanofiller onto the surface of carbon fiber. Mechanical properties of CE composites are a strong function of interfacial bond strength between carbon fiber and epoxy matrix. In this regard, improvement of the wettability of fibers by Electrophoretic deposition technique (EPD) is proposed to enhance the interfacial bond strength and hence the properties. CNT-OH/CNT-COOH nanofiller was incorporated onto carbon fibers via EPD technique, maintaining fixed concentration of nanofiller in the bath at constant current and deposition time. Uniform deposition of nanofiller onto the carbon fibers was confirmed by Field Emission Scanning Electron Microscopy (FESEM) studies. The nanofiller deposited carbon fibers were then used for the preparation of composites by hand layup technique. This laminate was subjected to 3-point bend test for estimation of flexural properties. It was reported that CNT-COOH-CE composite exhibited an increase of flexure strength by 10% and 7% when compared to unmodified CE and CNT-OH-CE composites respectively. To evaluate the effect on glass transition temperature (T g), Differential scanning calorimetry (DSC) was used. Also, the mode of failure in these composites were examined by fractographic study.