scholarly journals Mechanical Investigation of Epoxy Based High-Strength Carbon Fiber Braided Composites Modified with Silane Coupling Agents

Author(s):  
OĞUZ ERYILMAZ ◽  
Erhan SANCAK

Abstract Braiding technique is one of the most cost-effective and versatile methods to manufacture braided preforms for producing textile reinforced composites which have been utilized in a number of applications such as aerospace and automotive sectors. Carbon fiber is one of the most common reinforcing fibers having high strength and modulus used in high-performance composites. In this study, epoxy resin was modified with 3 – aminopropyltriethoxysilane (APTES) and 3 – aminopropylmethyldimethoxysilane (APMDMS) in order to enhance interfacial adhesion between matrix and carbon fiber. Composites were produced by vacuum-assisted resin infusion method (VARIM) using braided carbon fabrics and epoxy resin which was treated with silane at different concentrations (from 0.0% to 1.0%). Braided fabrics were manufactured from a high-strength standard modulus type of carbon fiber and using a radial braiding machine. According to the mechanical results, the ideal (optimum) concentration of APTES and APMDMS for the matrix modification has been around 0.5 wt% of the epoxy system. Also, the mechanical properties of APTES-treated epoxy composites are slightly higher than those of APMDMS-treated epoxy composites at the same concentration. When it is compared to silane untreated composite, 0.5 wt% of APTES/APMDMS silane treated epoxy/carbon braided composites have led to an increase of 7.71/6.16 and 7.65/6.05 % in tensile and flexural strength while the corresponding increase has resulted in 17.48/13.51 and 16.63/13.33 % in terms of tensile and flexural modulus, respectively. Impact testing results indicate that 0.5 wt% of APTES and APMDMS composites are improved 6.87 and 4.31 % compared to untreated composites, respectively.

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Fawad Inam ◽  
Doris W. Y. Wong ◽  
Manabu Kuwata ◽  
Ton Peijs

Amino-modified double wall carbon nanotube (DWCNT-NH2)/carbon fiber (CF)/epoxy hybrid micro-nanocomposite laminates were prepared by a resin infusion technique. DWCNT-NH2/epoxy nanocomposites and carbon fiber/epoxy microcomposites were made for comparison. Morphological analysis of the hybrid composites was performed using field emission scanning electron microscope. A good dispersion at low loadings of carbon nanotubes (CNTs) in epoxy matrix was achieved by a bath ultrasonication method. Mechanical characterization of the hybrid micro-nanocomposites manufactured by a resin infusion process included three-point bending, mode I interlaminar toughness, dynamic mechanical analysis, and drop-weight impact testing. The addition of small amounts of CNTs (0.025, 0.05, and 0.1 wt%) to epoxy resins for the fabrication of multiscale carbon fiber composites resulted in a maximum enhancement in flexural modulus by 35%, a 5% improvement in flexural strength, a 6% improvement in absorbed impact energy, and 23% decrease in the mode I interlaminar toughness. Hybridization of carbon fiber-reinforced epoxy using CNTs resulted in a reduction in and dampening characteristics, presumably as a result of the presence of micron-sized agglomerates.


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.


Author(s):  
Fei Liang ◽  
Jihua Gou ◽  
He Shen ◽  
Yunjun Xu ◽  
Bob Mabbott

Shape memory polymers (SMPs) are one of the most popular smart materials due to light weight and high elastic deformation capability. In this study, highly conductive carbon nanofibers paper (CNFP) was coated on the surface of SMP as a conductive layer for electro actuation of SMP. To overcome the drawback of low modulus and low strength of shape memory polymer (SMP), continuous carbon fiber reinforcement was also incorporated with SMP by autoclave processing. The dynamic mechanical analysis (DMA) result showed over 600% increase of storage modulus of SMP by introducing carbon fiber reinforcement. Also, the shape recovery time of SMP has been reduced over 150%, while the recovery ratio of SMP has been improved to 99% by incorporating with carbon fiber reinforcement. Additionally, the mechanical property degradation of SMP composites has been investigated after different electro actuation cycles. After 50 actuation cycles, the decrease of flexural modulus of SMP composites is negligible (< 2%), and the ultimate flexural strength of SMP composites only decreased 25%. The SMP composite shows high strength and modulus, and good durability.


2016 ◽  
Vol 245 (4) ◽  
pp. 271-279 ◽  
Author(s):  
Adam Wiśniewski ◽  
Anna Sałacińska ◽  
Jakub Wilk

2011 ◽  
Vol 287-290 ◽  
pp. 197-200
Author(s):  
Hai Qing Hu ◽  
Li Zhao ◽  
Jia Qiang Liu ◽  
Shi Bao Wen ◽  
Yong Jiang Gu ◽  
...  

Carbon fiber powder (CFP) instead of the traditional glass fiber (cloth) was used to reinforce epoxy resin for rapid tooling. There are two obvious advantages: one is to utilize the waste materials, which is good for the protection of the environment; another is to simplify the producing process by cast molding. The filling amount and dispersing process of CFP was studied in this paper. The results show that when the amount of CFP was 10 wt%, and the ultrasonic time is more than 15 min, the CFP can be dispersed in the epoxy matrix uniformly, and the mechanical properties can meet the requirement of epoxy molding.


2019 ◽  
Vol 21 (6) ◽  
pp. 1484-1497 ◽  
Author(s):  
Sheng Wang ◽  
Songqi Ma ◽  
Qiong Li ◽  
Xiwei Xu ◽  
Binbo Wang ◽  
...  

A high-performance epoxy vitrimer was facilely prepared from a renewable lignin derivative vanillin, and its carbon-fiber composites were nondestructively recycled.


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