FTIR and DSC studies on gamma irradiated P(VdF-HFP) fluoropolymers applied to dosimetry

Electron and gamma irradiation‐induced effects in poly(ethylene‐co‐tetrafluoroethylene) films

“…Over the entire band, the typical absorbance of hydroxyl (OH) in the broad band of 2400-3800 cm À1 is not found (Figure 1c,d). This is different from the previous observations for the irradiated ETFE, 29,56 poly(vinylidene fluoride-trifluorethylene) [P(VDF-TrFE)], 57,58 poly(vinylidene difluoride-co-hexafluoropropylene) [P(VDF-HFP)], 59 PTFE, 60 and PFA films. 61 In these irradiated polymers, the hydroxyl characteristic band was found even in the low-dose range either in air or in vacuum conditions.…”

“…The signatures at 1715 (peak I) and 1746 cm À1 (peak III) are assigned to the C C stretching vibrations of in-chain and terminal double bonds. 57,59,64,65 However, that a characteristic wavenumber of peak III (1746 cm À1 ) is higher than those of peak I (1715 cm À1 ) is due to the higher electronegativity of two F atoms in a CH CF 2 group (peak III) comparing to that of a CH CF group (peak I). At the same time, the presence of oxidation bonds possibly including ketone ( CO ) and acid fluoride ( COF) was previously identified at higher frequencies of 1730-1850 cm À1 .…”

“…Taking into account the above characteristic formations of CC and CO bonds, the band of 1680–1820 cm −1 is analyzed into six components using the GLS function (Figure 2c,d). The signatures at 1715 (peak I) and 1746 cm −1 (peak III) are assigned to the CC stretching vibrations of in‐chain and terminal double bonds 57,59,64,65 . However, that a characteristic wavenumber of peak III (1746 cm −1 ) is higher than those of peak I (1715 cm −1 ) is due to the higher electronegativity of two F atoms in a CHCF 2 group (peak III) comparing to that of a CHCF group (peak I).…”

“…Table 1 presents some other fluoropolymers that have been examined for application in radiation dosimeters. 57,59,[73][74][75][76] These fluoropolymers were tested mostly with gamma rays from 60 Co sources using FTIR, UV-Vis, electron paramagnetic resonance (EPR), electron spin resonance (ESR), and differential scanning calorimetry (DSC) measurements. The irradiated dose range was investigated from 0 to 2300 kGy.…”

Thermal analysis for study of the gamma radiation effects in poly(vinylidene fluoride)

“…However, in the region between 1450 and 1900 cm À 1 , it can observe a well pronounced increase of a wide absorption band centered at 1720 cm À 1 , for increasing gamma doses. In a previous work, this band was attributed to the sum of the increasing individual bands at 1715, 1730 and 1754 cm À 1 (Liz et al, 2011). According to Boullier et al (2003), these bands can be described as the stretch of C ¼C bonds (1715 and 1754 cm À 1 ) and C ¼O bonds (1730 cm À 1 ).…”