Thermostimulated CaSO/sub 4/:Mn storage phosphors mixed with P(VDF-TrFE)/PMMA blends applied to digital radiography

This work describes an investigation on the use of polymeric blends as the host material in flexible thermoluminescent (TL) films, for application in digital radiography. Polymeric films made of semi-crystalline poly(vinylidene fluoride-trifluorethylene) [P(VDF-TrFE)] copolymer blended with 0, 5,10, 15, 25, 30, and 35% wt. of amorphous poly(methyl methacrylate) [PMMA] were studied using differential scanning calorimetry (DSC) and UV-VIS spectrometry. Combining data from blend compatibility and melting temperature of the crystallites, we found out that the P(VDF-TrFE)/PMMA with contents of PMMA until 15% wt. can be used for hosting thermoluminescent materials. Above this value, there is no more compatibility between these materials, with the appearance of small clusters of PMMA. Among the candidates, the blend with 15% wt. shows the best optical transparence and thus it has been chosen as the optimal blend composition for use as host matrix in a TL film, once the thermoluminescent visible light emitted from the granules localized beneath the film surface has a higher probability of getting outside, without optical scattering. Digital radiographic images emitted from heated films made of CaSO₄ :Mn storage phosphor powder dispersed into these blends were captured using a standard charged coupled device (CCD). The quality of ithe obtained radiographic images shows that TL plastic films present high potential to be an alternative way to obtain digital images, commonly obtained by photoluminescence based devices or X ray sensitive CCD cameras