scholarly journals Thermal, Mechanical, and Microstructural Study of PBO Fiber during Carbonization

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 608 ◽  
Author(s):  
Weizhe Hao ◽  
Xuejun Zhang ◽  
Yanhong Tian
Keyword(s):  
Carbon Fiber ◽  
Mechanical Performance ◽  
Continuous Process ◽  
Carbonaceous Material ◽  
Inert Atmosphere ◽  
Treatment Temperature ◽  
Gravimetric Analysis ◽  
Graphite Crystallite ◽  
Pbo Fiber ◽  
Good Heat Resistance

Poly(p-phenylene benzobisoxazole) (PBO) fiber shows fascinating properties including excellent mechanical performance, high crystallinity, and fairly good heat resistance as a kind of polymer fiber. Its properties make it a possible candidate as a precursor of carbon fiber. This paper mainly investigates the possibility of yielding carbon fiber from PBO by direct carbonization using a continuous process and multiple properties of yielded fiber treated under different heat treatment temperature (HTT). The results show that PBO fiber was able to sustain an HTT as high as 1400 °C under the inert atmosphere and that the shape of fiber was still preserved without failure. Using thermal gravimetric analysis (TGA) and TGA coupled with mass spectroscopy (TGA-MS), it was found that a significant mass loss procedure happened around 723.3 °C, along with the emission of various small molecules. The mechanical performance first suffered a decrease due to the rupture of the PBO structure and then slightly increased because of the generating of graphite crystallite based on the broken structure of PBO. It was observed that PBO’s microstructure transformed gradually to that of carbonaceous material, which could be the reason why the change of mechanical performance happened.

Novel carbon foam composites reinforced with carbon fiber felt developed from inexpensive pitch precursor matrix

2020 ◽  
Vol 54 (24) ◽  
pp. 3559-3569
Author(s):  
Shishobhan Sharma ◽  
Rasmika H Patel
Keyword(s):  
Carbon Fiber ◽  
Elevated Temperatures ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Coal Tar ◽  
Carbon Foam ◽  
Petroleum Pitch ◽  
Gravimetric Analysis ◽  
Carbon Fiber Felt ◽  
Carbon Foams

Novel carbon foam composites derived from various pitch precursors have been fabricated and characterized. This paper specifically focuses on developing an effective process for fabricating the carbon foam composites from Polyacrylonitrile (PAN)-based carbon felt as a reinforcement and various readily available pitch matrix such as petroleum pitch, coal tar pitch, and mesophase pitch. The paper endeavors to develop the carbon foam composites and to carry out detailed morphological, thermal, and mechanical characterization. Traditional carbon foams have been known to offer poor mechanical performance, and hence, in this paper, the pitch-based carbon foams were innovatively reinforced with the PAN-based carbon fiber felt. Carbon foam composites were subjected to partial oxidation, and their morphological and mechanical response after the heat treatment was studied thoroughly. Thermal gravimetric analysis and thermal mechanical analysis techniques reveal an appreciable thermo-physical and thermo-mechanical response at elevated temperatures. Also, it was found out that the factors such as volatile content and quinoline insoluble fraction affect the morphology as well as the physical robustness on the composite foams.

Original Silk Pre-Oxidation Treatment of Carbon Fiber from Coal Tar Pitch

2014 ◽  
Vol 989-994 ◽  
pp. 194-198 ◽  
Author(s):  
Xue Fei Zhao ◽  
Yi Fan Wen ◽  
Tao Qi ◽  
Shi Quan Lai ◽  
Li Juan Gao
Keyword(s):  
Weight Loss ◽  
Carbon Fiber ◽  
Heating Rate ◽  
Mechanical Performance ◽  
Coal Tar ◽  
Ring Structure ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Oxidation Condition ◽  
Higher Temperature

In the preparing process of carbon fiber, the fiber mechanical performance is affected by the pre-oxidation condition. In this paper the pre-oxidation technology condition of the original silk is researched, and the functional group in the molecule and the process of thermal gravimetric of the original silk and pre-oxidized silk are investigated by the method of infrared spectroscopy analysis and thermal gravimetric analysis. The IR analysis shows that associated hydroxyl is disappeared, Ar-H is decreased substantially, and methyl and methylene of the ring structure are changed greatly in the molecule of pre-oxidized silk. The TG analysis shows that the first weight loss temperature is increased, weight loss temperature range is moved to the higher temperature direction, the total weight loss rate is decreased, and weight loss velocity is decreased substantially. The mechanical performance of carbon fiber is affected by the pre-oxidation heating rate. When pre-oxidation heating rate is 1.5°C/min, the breaking strength of carbon fiber is 1195.84Mpa and the Young's modulus is 80Gpa.

Determination of fiber volume fraction in a cured laminate

2021 ◽  
pp. 002199832110112
Author(s):  
Qing Yang Steve Wu ◽  
Nan Zhang ◽  
Weng Heng Liew ◽  
Vincent Lim ◽  
Xiping Ni ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Volume Fraction ◽  
Evaluation Method ◽  
Volume Fraction ◽  
Matrix Material ◽  
Volume Ratio ◽  
Gravimetric Analysis ◽  
Fiber Volume ◽  
Laser Ultrasonic ◽  
The Matrix

Propagation of ultrasonic wave in Carbon Fiber Reinforced Polymer (CFRP) is greatly influenced by the material’s matrix, resins and fiber volume ratio. Laser ultrasonic broadband spectral technique has been demonstrated for porosity and fiber volume ratio extraction on unidirection aligned CFRP laminates. Porosity in the matrix materials can be calculated by longitudinal wave attenuation and accurate fiber volume ratio can be derived by combined velocity through the high strength carbon fiber and the matrix material with further consideration of porosity effects. The results have been benchmarked by pulse-echo ultrasonic tests, gas pycnometer and thermal gravimetric analysis (TGA). The potentials and advantages of the laser ultrasonic technique as a non-destructive evaluation method for CFRP carbon fiber volume fraction evaluation were demonstrated.

Optimization of Curing Conditions and Nanofiller Incorporation for Production of High Performance Laminated Kevlar/Epoxy Nanocomposites

2018 ◽  
Author(s):  
Abdel-Hamid I. Mourad ◽  
Mouza S. Al Mansoori ◽  
Lamia A. Al Marzooqi ◽  
Farah A. Genena ◽  
Nizamudeen Cherupurakal
Keyword(s):  
Oil And Gas ◽  
Mechanical Performance ◽  
Thermo Gravimetric Analysis ◽  
Applied Pressure ◽  
Curing Temperature ◽  
Gravimetric Analysis ◽  
Epoxy Nanocomposites ◽  
Scanning Calorimetry ◽  
Curing Conditions ◽  
Weight Percentage

Kevlar composite materials are getting scientific interest in repairing of oil and gas pipelines in both offshore and onshore due to their unique properties. Curing is one of the major factor in deciding the final mechanical performance of laminated Kevlar/epoxy nanocomposites. The parameters such as curing time, temperature and applied pressure during the hot pressing will affect chemistry of crosslinking of the epoxy matrix and interaction of epoxy with the Kevlar fiber. The present study is carried out to evaluate the optimal curing conditions of the Kevlar/epoxy nanocomposites. Three different nanofillers (namely Multi walled Carbon nanotubes (MWCNT), Silicon Carbide (SiC) and Aluminum Oxide (Al2O3)) are incorporated in different weight percentage. Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA) tests are carried out to determine the thermal stability and optimal curing conditions. Mechanical performance is investigated by conducting flexure, and drop weight tests. The results show that, the optimal curing temperature for maximizing the mechanical properties is at 170°C. Peeling off the Kevlar layers are observed for nanocomposite samples cured under 100°C. Mechanical strength of the composites is enhanced by optimizing the curing conditions and nanofiller contents.

scholarly journals State-of-the-Art Review on Experimental Investigations of Textile-Reinforced Concrete Exposed to High Temperatures

2021 ◽  
Vol 5 (11) ◽  
pp. 290
Author(s):  
Panagiotis Kapsalis ◽  
Tine Tysmans ◽  
Danny Van Hemelrijck ◽  
Thanasis Triantafillou
Keyword(s):  
Reinforced Concrete ◽  
High Temperatures ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Experimental Investigations ◽  
Textile Reinforced Concrete ◽  
Structural Applications ◽  
Promising Solution ◽  
Good Heat Resistance

Textile-reinforced concrete (TRC) is a promising composite material with enormous potential in structural applications because it offers the possibility to construct slender, lightweight, and robust elements. However, despite the good heat resistance of the inorganic matrices and the well-established knowledge on the high-temperature performance of the commonly used fibrous reinforcements, their application in TRC elements with very small thicknesses makes their effectiveness against thermal loads questionable. This paper presents a state-of-the-art review on the thermomechanical behavior of TRC, focusing on its mechanical performance both during and after exposure to high temperatures. The available knowledge from experimental investigations where TRC has been tested in thermomechanical conditions as a standalone material is compiled, and the results are compared. This comparative study identifies the key parameters that determine the mechanical response of TRC to increased temperatures, being the surface treatment of the textiles and the combination of thermal and mechanical loads. It is concluded that the uncoated carbon fibers are the most promising solution for a fire-safe TRC application. However, the knowledge gaps are still large, mainly due to the inconsistency of the testing methods and the stochastic behavior of phenomena related to heat treatment (such as spalling).

Numerical and experimental evaluation of mechanical performance of the multifunctional energy storage composites

2021 ◽  
pp. 002199832110495
Author(s):  
Yinan Wang ◽  
Fu-Kuo Chang
Keyword(s):  
Energy Storage ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Fiber Composite ◽  
Mechanical Damage ◽  
Experimental Tests ◽  
Structural Element ◽  
Carbon Fiber Composite

This work presents numerical simulation methods to model the mechanical behavior of the multifunctional energy storage composites (MESCs), which consist of a stack of multiple thin battery layers reinforced with through-the-hole polymer rivets and embedded inside carbon fiber composite laminates. MESC has been demonstrated through earlier experiments on its exceptional behavior as a structural element as well as a battery. However, the inherent complex infrastructure of the MESC design has created significant challenges in simulation and modeling. A novel homogenization technique was adopted to characterize the multi-layer properties of battery material using physics-based constitutive equations combined with nonlinear deformation theories to handle the interface between the battery layers. Second, mechanical damage and failure modes among battery materials, polymer reinforcements, and carbon fiber-polymer interfaces were characterized through appropriate models and experiments. The model of MESCs has been implemented in a commercial finite element code in ABAQUS. A comparison of structural response and failure modes from numerical simulations and experimental tests are presented. The results of the study showed that the predictions of elastic and damage responses of MESCs at various loading conditions agreed well with the experimental data. © 2021

Influence of Coating on Mechanical Performance of Lap-Spliced Carbon Fiber-Textile Reinforced Mortar (TRM)

2019 ◽  
Vol 972 ◽  
pp. 64-68
Author(s):  
Gia Toai Truong ◽  
Ngoc Hieu Dinh ◽  
Sang Hyun Park ◽  
Seung Jae Lee ◽  
Joo Young Kim ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Aluminum Oxide ◽  
Mechanical Performance ◽  
Ultimate Strain ◽  
Oxide Powder ◽  
Peak Strength ◽  
Lap Splice ◽  
Aluminum Oxide Powder ◽  
Coating Methods ◽  
Textile Reinforced Mortar

In this study, the effect of coating methods in the lap splice area on mechanical performance of lap-spliced carbon textile reinforced mortar (TRM) composites was investigated. The coating methods included textile reinforcement coated with epoxy, textile reinforcement coated with aluminum oxide powder and epoxy, and textile reinforcement coated with aluminum oxide powder, epoxy, and carbon fiber fabrics. It appears that the coated specimens showed higher peak strength and ultimate strain than those of the uncoated one.

High-temperature effect on the mechanical performance of screwed CFRPI–TC4 alloy joints repaired with metal inserts

2019 ◽  
Vol 54 (17) ◽  
pp. 2245-2260
Author(s):  
Yun-Tao Zhu ◽  
Jun-Jiang Xiong
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Temperature Effect ◽  
Analytical Model ◽  
Joint Strength ◽  
Mechanical Performance ◽  
Joint Stiffness ◽  
Repair Efficiency ◽  
Strength And Stiffness ◽  
High Temperature Effect

This paper seeks to study high-temperature effect on mechanical performance of screwed single-lap carbon fiber-reinforced polyimide–TC4 titanium alloy joints repaired with metal inserts. Quasi-static tension tests were conducted at room temperature (RT) and 250℃ to determine the joint strength and stiffness of repaired joints with metal inserts. Based on the experimental results, high-temperature effect on joint strength and stiffness and insert repair efficiency were analyzed and discussed. A new analytical model was established to evaluate the effect of high temperature on joint stiffness. It is concluded that (1) joint strength and stiffness for all configurations are lower at 250℃ than that at RT, showing the expected detrimental effect of high temperature on joint strength and stiffness. The reductions in joint strength and stiffness depend on the joint configuration; (2) the repair efficiencies of embedded conical nut for joint strengths of protruding and countersunk head screw joints decrease, but those for joint stiffness increase at 250℃ as against at RT. Unlike the repair efficiencies of embedded conical nut, the repair efficiency of bushing for joint strength is slightly greater, but that for joint stiffness is less at 250℃ than at RT; and (3) the developed analytical model is capable of predicting the displacement of screwed single-lap carbon fiber-reinforced polyimide–TC4 joints at RT and high temperature, and there is good agreement between the experimental data and the predicted curves.

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