Improving crosslinking of stabilized polyacrylonitrile fibers and mechanical properties of carbon fibers by irradiating with γ-ray

Zhao, Weizhe; Lu, Youming; Wang, Jing; Chen, Qiang; Zhou, Liangxiao; Jiang, Junqi; Chen, Li

doi:10.1016/j.polymdegradstab.2016.07.018

Cited by 40 publications

(27 citation statements)

References 38 publications

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“…Previous reports have demonstrated that pretreatments, such as chemicals modification [15][16][17], irradiation modification [18][19][20][21][22][23], and thermal modification [24][25][26], could tune the exothermic behavior and the structural evolution of PAN fibers during stabilization. The KMnO 4 has been a famous chemical modification on PAN fibers [15][16][17], which can induce oxidation of PAN molecules.…”

Section: Introductionmentioning

confidence: 99%

“…The KMnO 4 has been a famous chemical modification on PAN fibers [15][16][17], which can induce oxidation of PAN molecules. The irradiation including UV irradiation, gamma-ray irradiation, plasma irradiation and so on causes cyclization of PAN molecules and aggregation structure of fibers [18][19][20][21][22][23]. Qin et al [24,25] has researched that thermal treatment of PAN fiber in nitrogen and nitrogen and vapor atmosphere to improve the stabilization extent of fibers [24], and to improve the preferred orientation and mechanical properties of carbon fibers [25].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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“…The third peak on the DSC trace recorded under synthetic air (exothermic region V) can be assigned to the cross-linking reactions of oxygen-containing functional groups [10].…”

Section: Oxidative Stabilization Of Pre-treated Panmentioning

confidence: 99%

“…The three reactions are called cyclization, dehydrogenation and oxidation (sometimes cross-linking), and they are usually assigned to the exothermic peaks of thermograms obtained in differential scanning calorimetric (DSC) measurements. PAN is studied predominantly in oxidative atmosphere, since the common industrial process used in practice is based on oxidative stabilization [2,4,5,9,10]. The approach yields complicated overlapping exothermic signals, the resolution of which depends primarily on the rate of heating and the weight of the sample used for DSC analysis.…”

Section: Introductionmentioning

confidence: 99%

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The mechanism of thermal stabilization of polyacrylonitrile

Szepcsik

Pukánszky

2019

Thermochimica Acta

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The two-step stabilization of a thoroughly characterized PAN homopolymer was studied by various methods including thermogravimetric analysis (TGA), evolved gas analysis (EGA), differential scanning calorimetry (DSC), Fourier transformed infrared spectroscopy (FTIR), oxygen microanalysis and theoretical energy calculations. Stabilization was carried out with pre-treatment in inert atmosphere, and the reactions taking

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Polymer‐Based Synthetic Routes to Carbon‐Based Metal‐Free Catalysts

2018

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Carbons are increasingly important as possible alternatives to expensive metal catalysts owing to the wide range of chemical properties they can exhibit and the growing set of synthetic routes available to produce them. This Progress Report discusses the process of making catalytic carbons from polymeric precursors, focusing on mechanisms of carbonization and how the polymer structures and synthetic procedures affect the resulting carbons. In considering what is necessary to move laboratory catalytic carbons to industrial and commercial applications, the cost and complexity to produce them are a considerable challenge to overcome. Industrially produced carbons are typically made from biopolymers such as lignin while many of the catalytic carbons studied in literature are from synthetic polymers. Thus, studying polymer-derived carbons can provide insights into the carbonization process and the properties of catalytic carbons, which can subsequently be translated to improve biopolymerderived carbons in an economical way. Aspects of polymer carbonization discussed include carbonization mechanisms, effects of crosslinkers, polymer microstructure, heteroatom control, and effects nanostructuring.

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Improving crosslinking of stabilized polyacrylonitrile fibers and mechanical properties of carbon fibers by irradiating with γ-ray

Cited by 40 publications

References 38 publications

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

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

The mechanism of thermal stabilization of polyacrylonitrile

Polymer‐Based Synthetic Routes to Carbon‐Based Metal‐Free Catalysts

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