The presence of polymeric material in radiolysed aqueous solutions of ammonium bicarbonate

A polymeric material is present in radiolysed aqueous solutions (O2-free) of ammonium bicarbonate (0.05 mol dm-3) at large doses of cobalt-60 gamma rays (0.15 - 1.7 MGy). Polymer is a secondary radiolytic product: its measurable amounts appear after about 0.15 MGy and increase with dose to become about 0.1 g dm-3 at 1.7 MGy. Throughout the dose range studied, the HPLC gives for molecular weight 16,000 -14,000 dalton, and the i.r. spectra show the presence of characteristic functional groups of CH2, CH, CO-3, COO-and NH4+. Possible chemical nature of polymeric material and its origin are considered. (author)