scholarly journals Rapid and Continuous Preparation of Polyacrylonitrile-Based Carbon Fibers with Electron-Beam Irradiation Pretreatment

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1270 ◽  
Author(s):  
Jia Yang ◽  
Yuchen Liu ◽  
Jie Liu ◽  
Zhigang Shen ◽  
Jieying Liang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Carbon Fibers ◽  
Thermal Stabilization ◽  
Beam Irradiation ◽  
Stabilization Time ◽  
Continuous Preparation ◽  
Energy Consuming ◽  
Time Savings ◽  
Time And Energy ◽  
Pan Fibers

Thermal stabilization is a critical, yet time- and energy-consuming process during the preparation of PAN-based carbon fibers. In this work, automobile-grade carbon fibers with a 2.85 GPa tensile strength and a 203 GPa modulus are continuously produced with electron-beam (e-beam) irradiation pretreatment and 24 min thermal stabilization. Thermal and structural analyses reveal that e-beam irradiation can lower the onset temperature of the cyclization reaction and mitigate the heat release. Meanwhile, during the process of stabilization, e-beam irradiation can facilitate the evolution of both the chemical structure and the crystalline structure of polyacrylonitrile (PAN) fibers. Comparing to the industrial production of carbon fiber with a 40 min stabilization time, e-beam irradiated PAN fibers can achieve the same degree of stabilization with a 40% time savings.

scholarly journals Influence of boric acid on radial structure of oxidized polyacrylonitrile fibers

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 79-86
Author(s):  
Xue-Fei Wang ◽  
Xiao-Long Zhu ◽  
Chi Jiang ◽  
Jian-Min Guan ◽  
Xin Qian ◽  
...  
Keyword(s):  
Boric Acid ◽  
Carbon Fibers ◽  
High Performance ◽  
Boron Content ◽  
Fiber Surface ◽  
Thermal Stabilization ◽  
Stabilization Time ◽  
Radial Structure ◽  
Stabilization Temperature ◽  
Pan Fibers

AbstractThe surface modification of polyacrylonitrile (PAN) fibers with boric acid was utilized to modulate the homogeneity of the radial structure of the PAN fibers during thermal stabilization. Exothermic peaks of the fibers were put off by boric acid, and unreacted nitrile groups of the oxidized PAN fibers increased with the boron content, indicating that boric acid on the fiber surface had an retardant effect on the thermal stabilization of PAN fibers. The relative skin thicknesses of the oxidized PAN fibers were quantitatively measured by sulfuric acid etching and SEM observation. The value increased obviously with the boron content, which could be further elevated by increasing stabilization time or decreasing stabilization temperature. Oxidized PAN fibers with more homogeneous radial structure can thus be obtained with the modification of boric acid, which might be beneficial for the preparation of high performance carbon fibers.

scholarly journals Structural Transformation of Polyacrylonitrile (PAN) Fibers during Rapid Thermal Pretreatment in Nitrogen Atmosphere

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 63 ◽  
Author(s):  
Wei Dang ◽  
Jie Liu ◽  
Xiaoxu Wang ◽  
Kaiqi Yan ◽  
Aolin Zhang ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Low Cost ◽  
Structural Evolution ◽  
Structural Difference ◽  
Nitrogen Atmosphere ◽  
Thermal Pretreatment ◽  
Scanning Calorimetry ◽  
Light Yellow ◽  
Time And Energy ◽  
Pan Fibers

The modification before the stabilization process could tune the exothermic behavior and the structural evolution of PAN fibers during stabilization. In this study, we demonstrate that a rapid thermal pretreatment in nitrogen can effectively mitigate the exothermic behavior of PAN fibers, such as decreasing the initial temperature, broadening the exothermal peak, and decreasing the nominal heat release during heating the fibers in air. The color of fibers has shown gradual changes from white to light yellow, yellow and brown during thermal pretreatment in nitrogen with the increase of pretreating temperature and time. The differential scanning calorimetry (DSC), Fourier Transform Infrared Spectrometer (FTIR), X-ray diffraction (XRD), and Thermogravimetric Analysis (TG) characterization have been applied to analyze the thermal properties, chemical and physical structural difference between PAN, and thermally pretreated PAN fibers. The thermal pretreatment of PAN fibers in nitrogen could induce cyclization, dehydrogenation, and cross-linking reactions, in which the cyclization play an important role on improving the cyclization index of stabilized PAN fibers. Meanwhile, the pretreatment can result in noticeable changes of the aggregation structure of PAN fibers, as indicated by the increase of crystallinity and crystalline size. These structural modifications can benefit the main cyclization reaction during stabilization and enhance the carbon yield in resultant carbon fibers. The rapid thermal pretreatment in nitrogen could increase efficiency of modification on PAN fibers, and that could save much time and energy. It is beneficial to manufacture low-cost carbon fibers and to spread the applications of carbon fibers.

scholarly journals Stabilization of pitch-based carbon fibers accompanying electron beam irradiation and their mechanical properties

2015 ◽  
Vol 16 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Mi-Seon Park ◽  
Yoonyoung Ko ◽  
Min-Jung Jung ◽  
Young-Seak Lee
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Carbon Fibers ◽  
Electron Beam Irradiation ◽  
Beam Irradiation

Preparation and characterization of polyacrylonitrile-based carbon fibers produced by electron beam irradiation pretreatment

2014 ◽  
Vol 20 (5) ◽  
pp. 3789-3792 ◽  
Author(s):  
Hye Kyoung Shin ◽  
Mira Park ◽  
Phil Hyun Kang ◽  
Heung-Soap Choi ◽  
Soo-Jin Park
Keyword(s):  
Electron Beam ◽  
Carbon Fibers ◽  
Electron Beam Irradiation ◽  
Beam Irradiation

Effects of Thermal Stabilization and Electron Beam Irradiation on the Characteristics of Lignin Extracted from Black Liquor

2017 ◽  
Vol 381 ◽  
pp. 64-68
Author(s):  
Dae Kyun Hwang ◽  
Jeong Ho Kim ◽  
Oh Hyeong Kwon ◽  
Won Ho Park ◽  
Dong Hwan Cho
Keyword(s):  
Heat Treatment ◽  
Electron Beam ◽  
Industrial Waste ◽  
Electron Beam Irradiation ◽  
Treatment Process ◽  
Black Liquor ◽  
Thermal Stabilization ◽  
Heat Treatment Process ◽  
Beam Irradiation ◽  
Stabilization Process

In the present work, lignin extracted from black liquor, which is industrial waste of pulp manufacturing. The extracted lignin was irradiated at various electron beam intensities from 100 to 1000 kGy. Also, the extracted lignin was thermally stabilized by heat treatment process. The characteristics of the stabilized and irradiated lignin materials were examined by means of TGA, ATR-FTIR, EA, and SEM. The ATR-FTIR result shows that both stabilized and irradiated lignin samples exhibit the decrease of characteristic absorption peaks, indicating the presence of guaiacyl and syringyl groups in the lignin structure. It reveals that the irradiation done to the ‘as-extracted’ lignin with appropriate electron beam intensity provides an efficiency as thermal stabilization of the lignin, suggesting that electron beam irradiation may apply directly to the extracted lignin, prior to carbonization the lignin without thermal stabilization process.

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