Investigation of poly(vinylidene fluoride) copolymers applied to high gamma dose dosimetry

Poly(vinylidene fluoride) (PVDF) is a semicrystalline linear homopolymer worldwide known by its good chemical, mechanical and electromechanical properties. Its polymeric chain is composed by the repetition of CH2-CF2 monomers. PVDF and some of its copolymers has demonstrated to be sensitive to ionizing radiation. Their piezoelectric properties are highly enhanced after ultraviolet, electrons or gamma irradiation. The sensibility of PVDF and its copolymers to ionizing radiation has encouraged us to investigate their use for high dose gamma dosimetry. In this work it is reported the relationship between the delivered gamma doses and the optical absorption (OA) at wavelengths raging from 190 to 900 nm. Particularly, the study is focused in the optical absorption peaks at 185 nm, 223 nm and 274 nm, once it has been demonstrated that they are related to the appearing of C=C conjugated bonds after X-ray and UV irradiation. It is demonstrated that there is a linear correlation between the gamma dose and the peak intensity at 223.5 nm for gamma doses ranging from 0.3 kGy to 13 kGy. Based on these results, it is concluded that PVDF fluorinated copolymer is a good candidate for use in high dose gamma dosimetry applications. (author)