Electron-beam-induced cyclisation to obtain C-fibre precursors from polyacrylonitrile homopolymers

Dietrich, Johann; Hirt, P.; Herlinger, Heinz

doi:10.1016/0014-3057(95)00185-9

Cited by 43 publications

(29 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recently, pioneering works have been performed by researchers to shorten the thermal stabilization time by ionizing radiation (gamma-ray or electron-beam) or plasma treatment prior to or during stabilization14151617. Among these technologies, electron-beam irradiation was found to be an especially powerful tool for treating polymer fibers.…”

mentioning

confidence: 99%

Comprehensive stabilization mechanism of electron-beam irradiated polyacrylonitrile fibers to shorten the conventional thermal treatment

Park

Yoo

Kang

et al. 2016

Sci Rep

View full text Add to dashboard Cite

An electron beam was irradiated on polyacrylonitrile (PAN) fibers prior to thermal stabilization. The electron-beam irradiation effectively shortened the thermal stabilization process by one fourth compared with the conventional thermal stabilization process. A comprehensive mechanistic study was conducted regarding this shortening of the thermal stabilization by electron-beam irradiation. Various species of chain radicals were produced in PAN fibers by electron-beam irradiation and existed for a relatively long duration, as observed by electron spin resonance spectroscopy. Subsequently, these radicals were gradually oxidized to peroxy radicals in the presence of oxygen under storage or heating. We found that these peroxy radicals (CO) enabled such an effective shortcut of thermal stabilization by acting as intermolecular cross-linking and partial aromatization points in the low temperature range (100–130 °C) and as earlier initiation seeds of successive cyclization reactions in the next temperature range (>130–140 °C) of thermal stabilization. Finally, even at a low irradiation dose (200 kGy), followed by a short heat treatment (230 °C for 30 min), the PAN fibers were sufficiently stabilized to produce carbon fibers with tensile strength and modulus of 2.3 and 216 GPa, respectively, after carbonization.

show abstract

mentioning

confidence: 99%

Comprehensive stabilization mechanism of electron-beam irradiated polyacrylonitrile fibers to shorten the conventional thermal treatment

Park

Yoo

Kang

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…CF production also inevitably includes processes that require considerable energy, such as a stabilization process in oxidative atmosphere, and a carbonization process under inert gas streams [7]. Atmospheric pressure plasmas [8,9] and electron beams [10] have been discussed as alternatives to conventional thermal stabilization processes because their adoption has been shown to be time saving or energy saving, which leads to the reduction in process cost. Replacing existing thermal carbonization processes with the use of microwave plasmas is also being considered as a more energy efficient process [11].…”

Section: Introductionmentioning

confidence: 99%

Two step microwave plasma carbonization including low plasma power pre-carbonization for polyacrylonitrile based carbon fiber

Kim

Kim²,

Choi

et al. 2015

Polymer

View full text Add to dashboard Cite

“…Photo-stabilization of PAN, especially at elevated temperatures, forms a cyclized ladder polymer structure. Electron beam irradiation generates free radicals in PAN, which aid cyclization and crosslinking [6] . Radical-induced cyclization and intermolecular crosslinking through the nitrile groups has been reported for PAN via ion beam [7] , X-ray [8] , gamma [9,10] and UV irradiation [5,11] .…”

Section: Introductionmentioning

confidence: 99%

“…The radiation chemistry of polymers has become of great interest in recent times. Photo-induced crosslinking of PAN has been reported in the literature [5][6][7][8][9][10][11] . Photo-stabilization of PAN, especially at elevated temperatures, forms a cyclized ladder polymer structure.…”

Section: Introductionmentioning

confidence: 99%

Effect of UV irradiation on PAN precursor fibers and stabilization process

Yuan

Wang

et al. 2011

J. Wuhan Univ. Technol.-Mat. Sci. Edit.

View full text Add to dashboard Cite

A low-cost rout for modifi cation the polyacrylontrile(PAN) precursor fi bers was developed. The approach involved pretreatment PAN precursor fibers with UV irradiation for various periods of time before the fibers were stabilized. The effect of UV irradiation on the chemical structure, orientation factor, density, crystallite size and morphology of the fi bers in the process of stabilization was characterized by use of fourier transform infrared spectroscopy(FTIR), fl oat-sink procedure, X-ray diffraction(XRD), scanning electron microscope(SEM), respectively. The results showed that UV irradiation could increase the density of the fi bers in stabilization process. FTIR analysis indicated that the cyclization of nitrile groups was initiated at room temperature by UV irradiation. The transformation of C≡N groups to C=N ones was accelerated in the process of stabilization. The orientation factor of irradiated fi bers was also increased. The crystallite size was decreased at fi rst and increased later, and the better irradiation time of UV was 3 min according to the XRD test. SEM analysis indicated that irradiation could decrease the internal and surface defects of the stabilized fi bers treated at 300 ℃.

show abstract

Electron-beam-induced cyclisation to obtain C-fibre precursors from polyacrylonitrile homopolymers

Cited by 43 publications

References 10 publications

Comprehensive stabilization mechanism of electron-beam irradiated polyacrylonitrile fibers to shorten the conventional thermal treatment

Comprehensive stabilization mechanism of electron-beam irradiated polyacrylonitrile fibers to shorten the conventional thermal treatment

Two step microwave plasma carbonization including low plasma power pre-carbonization for polyacrylonitrile based carbon fiber

Effect of UV irradiation on PAN precursor fibers and stabilization process

Contact Info

Product

Resources

About