The Effect of Gamma Irradiation on Phase Transitions in Polytetrafluoroethylene Doped with Silicon Dioxide of Plant Origin

Egorov, V. M.; Yakushev, P. N.; Arsent’ev, M. A.; Smolyanskiĭ, A. S.

doi:10.1134/s1063783420080132

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…It should be noted that the presence of crystals in the triclinic conformation in the crystalline phase of PTFE, which determine its composition in the temperature range below a phase transition temperature of 19 • C, can significantly increase the density of PTFE [58]. At the same time, when studying the structure of composite materials based on TRM-PTFE filled with silicon dioxide particles, it was shown that the phase transitions in PTFE are "smoothed" [59]. Consequently, the crystalline phase in PTFE at room temperature can consist of both "triclinic" and "hexagonal" crystals, which possibly form observed two components of the diffraction maximum hkl = 100 in the X-ray spectra of PTFE.…”

Section: Comparative Analysis Of the Experimentally Established As Well As Obtained From X-ray Data Density Values Of The Initial And Thementioning

confidence: 99%

Structure of Polytetrafluoroethylene Modified by the Combined Action of γ-Radiation and High Temperatures

et al. 2021

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By means of X-ray computed microtomography (XCMT), the existence of a developed porous structure with an average pore diameter of ~3.5 μm and pore content of ~1.1 vol.% has been revealed in unirradiated polytetrafluoroethylene (PTFE). It has been found that the combined action of gamma radiation (absorbed dose per PTFE of ~170 kGy) and high temperatures (327–350 °C) leads to the disappearance of the porous structure and the formation of several large pores with sizes from 30 to 50 μm in the bulk of thermal-radiation modified PTFE (TRM-PTFE). It has been established by X-ray diffraction (XRD) analysis that the thermal-radiation modification of PTFE leads to an increase in the interplanar spacings, the degree of crystallinity and the volume of the unit cell, as well as to a decrease in the size of crystals and the X-ray density of the crystalline phase in comparison with the initial polymer. It is assumed that the previously-established effect of improving the deformation-strength and tribological properties of the TRM-PTFE can be due not only to the radiation cross-linking of polymer chains but also to the disappearance of the pore system and to the ordering of the crystalline phase of PTFE

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Section: Comparative Analysis Of the Experimentally Established As Well As Obtained From X-ray Data Density Values Of The Initial And Thementioning

confidence: 99%

Structure of Polytetrafluoroethylene Modified by the Combined Action of γ-Radiation and High Temperatures

et al. 2021

View full text Add to dashboard Cite

show abstract

“…It should be noted that the presence of crystals in the triclinic conformation in the crystalline phase of PTFE, which determine its composition in the temperature range below a phase transition temperature of 19°C, can significantly increase the density of PTFE [32]. At the same time, when studying the structure of composite materials based on TRM-PTFE filled with silicon dioxide particles, it was shown that the phase transitions in PTFE are "smoothed" [33]. Consequently, the crystalline phase in PTFE at room temperature can consist of both "triclinic" and "hexagonal" crystals, which possibly form observed two components of the diffraction maximum hkl = 100 in the X-ray spectra of PTFE.…”

Section: Comparative Analysis Of the Experimentally Established As Well As Obtained From X-ray Data Density Values Of The Initial And Thementioning

confidence: 99%

Structure of polytetrafluoroethylene modified by the combined action of γ-radiation and high temperatures

Smolyanskiĭ¹,

Политова²,

Koshkina³

et al. 2021

Preprint

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By means of X-ray computed microtomography (XCMT) the existence of a developed microporous structure having an average pore diameter of ~3.5 μm and pore content of ~1.1 vol.% has been revealed in unirradiated polytetrafluoroethylene (PTFE). It has been found that the combined action of gamma radiation (absorbed dose per PTFE of ~170 kGy) and high temperatures (327-350 °C) leads to the disappearance of the microporous structure and the formation of several large pores with sizes from 30 to 50 μm in the bulk of thermal-radiation modified PTFE (TRM-PTFE). It has been established by X-ray diffraction (XRD) analysis that the thermal-radiation modification of PTFE leads to an increase in the interplanar spacings, the degree of crystallinity and volume of the unit cell, as well as to a decrease in the size of crystals and the X-ray density of the crystalline phase in comparison with the initial polymer. It is assumed that the previously established effect of improving the deformation-strength and tribological properties of the TRM-PTFE can be due not only to the radiation cross-linking of polymer chains but also to the disappearance of the micropore system and to the ordering of the crystalline phase of PTFE.

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Acoustic shock wave-induced short-range ordered graphitic domains in amorphous carbon nanoparticles and correlation between magnetic response and local atomic structures

Aswathappa,

Dai,

Sathiyadhas

et al. 2024

Diamond and Related Materials

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The Effect of Gamma Irradiation on Phase Transitions in Polytetrafluoroethylene Doped with Silicon Dioxide of Plant Origin

Cited by 4 publications

References 8 publications

Structure of Polytetrafluoroethylene Modified by the Combined Action of γ-Radiation and High Temperatures

Structure of Polytetrafluoroethylene Modified by the Combined Action of γ-Radiation and High Temperatures

Structure of polytetrafluoroethylene modified by the combined action of γ-radiation and high temperatures

Acoustic shock wave-induced short-range ordered graphitic domains in amorphous carbon nanoparticles and correlation between magnetic response and local atomic structures

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