Stability of polymeric scintillating resins developed for ultra-trace level detection of alpha- and beta-emitting radionuclides

This contribution characterizes the stability of scintillating resins for ionizing radiation detection that were synthesized with 2-(1-naphthyl)-5-phenyloxazole (α-NPO) or 2-(1-naphthyl)-4-vinyl-5-phenyloxazole (v-NPO) fluor in polystyrene (PS) or poly(4-methyl styrene) (PVT) matrices. Leaching studies of the PS and PVT resins with methyl acetate show a 60 % reduction in luminosity and 80 % reduction in detection efficiency for α-NPO samples; while v-NPO resins retained detection properties. Degradation studies indicate the nitration of PS resins and the fluors after nitric acid exposure, resulting in a 100 % reduction in optical properties; whereas PVT resins with v-NPO fluor maintained 20 % detection efficiency. Heuristics are reported for designing stable scintillating resins. (author)