Effects of the addition of MWCNT and ZrO2 nanoparticles on the dosimetric properties of PVDF

Abstract

The industrial application of radiation processing involves high doses of gamma or electron radiation to cause structural changes in materials, such as rubber vulcanization and polymer degradation, among others. A reliable dosimetric system is necessary to guarantee the desired effects and also to avoid damages. Poly(vinylidene fluoride) [PVDF] homopolymer has been recently proposed for application in high gamma dose dosimetry. In this work, nanocomposites made of PVDF filled with zirconium oxide [ZrO2] nanoparticles and multiwalled carbon nanotubes [MWCNT] were studied for applications in high dose dosimetry, for doses ranging from 100.0 kG to 2.72 MGy. Pristine PVDF and PVDF/MWCNT-ZrO2 samples were exposed to a Co-60 source. FTIR spectra were collected 2 h, 30 and 60 days after exposure. The intensity of the radio-induced absorption bands centered at 1715 cm−1 and 1730 cm−1 were found to have an unambiguous relationship with the absorbed dose. The pristine PVDF samples show linear behavior in the dose range between 100 and 1000 kGy. However, the PVDF/MWCNT-ZrO2 samples show linearity in a larger range, i.e. between 500 and 2750 kGy interval. The melting latent heat, measured by Differential Scanning Calorimetry (DSC) and SEM micrographs revealed that PVDF/MWCNT-ZrO2 samples show increased resistance to the radio-induced damages, when compared to pure PVDF samples irradiated in the same conditions. The results indicate that the MWCNT-ZrO2 adds resistance to PVDF and improves its dosimetric properties.