A Study on Thermal and Electrical Conductivities of Ethylene-Butene Copolymer Composites with Carbon Fibers

2021 ◽  
Vol 36 (4) ◽  
pp. 417-422
Author(s):  
Y. Hamid ◽  
P. Svoboda

Abstract Ethylene-butene copolymer (EBC)/carbon-fiber (CF) composites can be utilized as an electromechanical material due to their ability to change electric resistance with mechanical strain. The electro-mechanical properties and thermal conductivity of ethylene butene copolymer (EBC) composites with carbon fibers were studied. Carbon fibers were introduced to EBC with various concentrations (5 to 25 wt%). The results showed that carbon fibers’ addition to EBC improves the electric conductivity up to 10 times. Increasing the load up to 2.9 MPa will raise the electric resistance change by 4 500% for a 25% fiber sample. It is also noted that the EBC/CF composites’ electric resistance underwent a dramatic increase in raising the strain. For example, the resistance change was around 13 times higher at 15% strain compared to 5% strain. The thermal conductivity tests showed that the addition of carbon fibers increases the thermal conductivity by 40%, from 0.19 to 0.27 Wm–1K–1.

Author(s):  
Yasin Hamid ◽  
Petr Svoboda ◽  
Dagmar Svobodová

The electrical, mechanical and thermal conductivity of ethylene butene copolymer (EBC) composites with carbon fibers were studied. EBC/carbon-fiber composites can be utilized as an electro-mechanical material which is capable of changing it electric resistance with mechanical strain. Carbon fibers were introduced to EBC with different concentrations (5-25 wt%). The results showed that the addition of carbon fibers to EBC could increase the electric resistance up to 10 times. Increasing the load to 2.9 MPa could increase the electric resistance change by 4500% compared 25% fiber sample with pure EBC. It is also noted that the electric resistance of the EBC/CF composites underwent a dramatic increase with raising the strain, for example, the resistance change was around 13 times more at 15% strain in comparison to 5% of strain; The thermal conductivity tests showed that the addition of carbon fibers could increase the thermal conductivity by 40%, from 0.19 to 0.27 (Wm-1K-1). It was also observed that the addition of carbon fibers to EBC could increase the thermal conductivity.


1995 ◽  
Vol 383 ◽  
Author(s):  
Jyh-Ming Ting

ABSTRACTIn contrast to the form in which other carbon fibers are produced, vapor grown carbon fiber (VGCF) is produced from gas phase precursors in the form of individual fibers of discrete lengths. VGCF can be harvested as a mat of semi-aligned, semicontinuous fibers, with occasional fiber branching and curling. The use of VGCF mats as reinforcement result in composites which exhibit unique microstructure and physical properties that are not observed in other types of carbon composites. This paper describes the processing of VGCF mats reinforced carbon composites, and its unique microstructure and properties. Utilization of fiber tensile properties, as well as thermal conductivity, in the composites is discussed. Comparison of experimental results from various VGCF composites to theory indicates that mechanical properties are more strongly affected by characteristics of VGCF mat than are thermal conductivity. The implications of this relationship favors applications for thermal management where structural demands are less stringent.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 954 ◽  
Author(s):  
Jing Li ◽  
Rubai Lei ◽  
Jinfeng Lai ◽  
Xuyang Chen ◽  
Yang Li

The high thermal conductivity and stability, outstanding mechanical properties, and low weight make graphene suitable for many applications in the realm of thermal management, especially in high integration systems. Herein, we report a high-performance, low-temperature reduced graphene oxide/magnetic carbon fiber composite film. Magnetic carbon fibers were prepared using a co-precipitation method, and the graphene oxide solution was prepared using an improved Hummers’ method. The magnetic carbon fibers were orientated by magnetite and immersed in the graphene oxide solution during filtration, followed by annealing at 800 °C. The composite film exhibited improved thermal conductivity (over 600 W/m·K) and mechanical properties (tensile strength of 37.1 MPa and bending cycle of up to 8000). The experimental results illustrate that the graphene in the composite membrane provides heat transfer channels to promote in-plane thermal conductivity, while the magnetic carbon fiber acts as a scaffold to reinforce the mechanical properties and improve the quality of the graphene. Due to the synergistic effect of the graphene and magnetic carbon, this composite has wide potential applications in heat dissipation.


2018 ◽  
Vol 225 ◽  
pp. 01022
Author(s):  
Falak O. Abasi ◽  
Raghad U. Aabass

Newer manufacturing techniques were invented and introduced during the last few decades; some of them were increasingly popular due to their enhanced advantages and ease of manufacturing over the conventional processes. Polymer composite material such as glass, carbon and Kevlar fiber reinforced composite are popular in high performance and light weight applications such as aerospace and automobile fields. This research has been done by reinforcing the matrix (epoxy) resin with two kinds of the reinforcement fibers. One weight fractions were used (20%) wt., Epoxy reinforced with chopped carbon fiber and second reinforcement was epoxy reinforced with hybrid reinforcements Kevlar fiber and improved one was the three laminates Kevlar fiber and chopped carbon fibers reinforced epoxy resin. After preparation of composite materials some of the mechanical properties have been studied. Four different fiber loading, i.e., 0 wt. %, 20wt. % CCF, 20wt. % SKF, AND 20wt. %CCF + 20wt. % SKF were taken for evaluating the above said properties. The thermal and mechanical properties, i.e., hardness load, impact strength, flexural strength (bending load), and thermal conductivity are determined to represent the behaviour of composite structures with that of fibers loading. The results show that with the increase in fiber loading the mechanical properties of carbon fiber reinforced epoxy composites increases as compared to short carbon fiber reinforced epoxy composites except in case of hardness, short carbon fiber reinforced composites shows better results. Similarly, flexural strength test, Impact test, and Brinell hardness test the results show the flexural strength, impact strength of the hybrid composites values were increased with existence of Kevlar fibers, while the hardness was decrease. But the reinforcement with carbon fibers increases the hardness and decreases other tests.


2010 ◽  
Vol 4 (4) ◽  
pp. 329-337
Author(s):  
Fabio Pereira ◽  
◽  
Fabiana Vieira ◽  
Luiz de Castro ◽  
Ricardo Michel ◽  
...  

In this work the influence of different configurations in the sample preparation process on commercial polyacrylonitrile-based carbon fibers mechanical tests were studied. Mechanical properties, such as tensile strength, Young’s modulus, elongation and Weibull modulus, were evaluated. The results showed that all sample preparation steps may have strong influence on the results.


2020 ◽  
Vol 869 ◽  
pp. 488-493
Author(s):  
Aues A. Beev ◽  
Svetlana Yu. Khashirova ◽  
Azamat L. Slonov ◽  
Ismel V. Musov ◽  
Azamat Zhansitov ◽  
...  

The article presents the results of sizing of discrete carbon fibers with various substances and their effect on the properties of polyetherimide composites. As sizing agents, 1,3-diaminobenzene, 4,4'-dihydroxy-2,2-diphenylpropane, polyetherimide and oligoetherether sulfone were used. The study of physical and mechanical properties showed that all the substances used increase the properties of the carbon-filled composite based on polyetherimide. The highest mechanical properties are demonstrated by a composite containing carbon fibers treated with 1,3-diaminobenzene, which indicates improved compatibility of the filler and the polymer matrix and enhanced intermolecular interactions.


1989 ◽  
Vol 4 (6) ◽  
pp. 1339-1346 ◽  
Author(s):  
C. T. Ho ◽  
D. D. L. Chung

Unidirectional and continuous carbon fiber tin-matrix composites were used for the packaging of the high-temperature superconductor YBa2Cu3O7–δ by diffusion bonding at 170 °C and 500 psi. Tin served as the adhesive and to increase the ductility, the normal-state electrical conductivity, and the thermal conductivity. Carbon fibers served to increase the strength and the modulus, both in tension along the fiber direction and in compression perpendicular to the fiber layers, though they decreased the strength in compression along the fiber direction. Carbon fibers also served to increase the thermal conductivity and the thermal fatigue resistance. At 24 vol. % fibers, the tensile strength was approximately equal to the compressive strength perpendicular to the fiber layers. With further increase of the fiber content, the tensile strength exceeded the compressive strength perpendicular to the fiber layers, reaching 134 MPa at 31 vol. % fibers. For fiber contents less than 30 vol. %, the compressive ductility perpendicular to the fiber layers exceeded that of the plain superconductor. At 30 vol. % fibers, the tensile modulus reached 15 GPa at room temperature and 27 GPa at 77 K. The tensile load was essentially sustained by the carbon fibers and the superconducting behavior was maintained after tension almost to the point of tensile fracture. Neither Tc nor Jc was affected by the composite processing.


2018 ◽  
Vol 774 ◽  
pp. 410-415 ◽  
Author(s):  
Kazuto Tanaka ◽  
Ken Uzumasa ◽  
Tsutao Katayama

Carbon fiber reinforced thermoplastics (CFRTP) are expected to be used as a structural material for aircraft and automobiles not only for their mechanical properties such as high specific strength and high specific rigidity but also for their high recyclability and short molding time. Generally, in a composite material having a laminated structure, interlaminar delamination is often caused by an out-of-plane impact, so the interlayer property plays an important role in the mechanical properties. It has been reported that the fiber/matrix interfacial strength increases by grafting carbon nanotubes (CNT) on the carbon fiber surface. In this study, CNT grafted carbon fibers were used for reinforcement of CFRTP laminate for the improvement of impact properties of CFRTP laminates. The impact absorbed energy of the CFRTP laminate using CNT grafted carbon fibers as reinforcing fiber was higher than that using untreated CF.


2020 ◽  
pp. 073168442095739
Author(s):  
Christopher Meninno ◽  
Vijaya Chalivendra ◽  
Yong Kim

An experimental study was conducted to investigate the electro-flexure response of conductive natural fiber hybrid laminate composites. The composites were composed of laminates of jute and flax fibers, and the composites were subjected to flexural loading for the electrical and bending response. Multi-walled carbon nanotubes were shear mixed and ultrasonicated into the epoxy matrix. Short carbon fibers were reinforced in-between the laminates using “wet flocking” technique. To measure the electrical response under flexural loading, a four-point circumferential probe method was used. A parametric study was conducted to investigate flexural performance and damage sensing by varying carbon fiber lengths (150 and 350 µm) and the carbon fiber densities (500, 1000, 1500, and 2000 fibers/mm2). The addition of carbon fibers decreased the flexural strength for most of the cases, however increased the flexural strain at break for all composites of carbon fiber length of 150 µm. During the nonlinear deformation, the composites of carbon fiber length of 150 µm demonstrated a linear increase in resistance; however, that of carbon fiber length of 350 µm showed increasing slope of resistance. Overall, the composites of carbon fiber length of 350 µm showed lower resistance change at break compared to that of carbon fiber length of 150 µm.


2020 ◽  
pp. 095400832095739
Author(s):  
Zibao Jiao ◽  
Zhengjun Yao ◽  
Jintang Zhou ◽  
Pengshu Yi ◽  
Chuanjun Lu

Based on the surface analysis of carbon fiber, an epoxy resin matrix with good wettability to carbon fibers had been developed and studied, and the influence of winding tension on the interface and mechanical properties of the composite were studied. The surface morphology of carbon fiber and the active functional groups of sizing agent were analyzed. In order to form a good interface combination, the wettability between carbon fibers and epoxy resin matrix was characterized by dynamic contact angle. The winding tension played an important role in the mechanical properties of composites. Therefore, a kind of carbon fiber reinforced composites, Naval Ordnance Laboratory (NOL) rings were fabricated using different winding tensions. Particularly, when the winding tension was 30 N, the interfacial bonding between carbon fibers and resin matrix was the most compact and firm. The tensile strength and interlaminar shear strength (ILSS) of NOL rings reached high values, 2712 MPa and 75 MPa, respectively.


Sign in / Sign up

Export Citation Format

Share Document