Obtaining polyacrylic acid labelled with tritium and deuterium

The polyacrylic hydrogels are a technological alternative for the storage of tritium liquid wastes with low and intermediate activity. β radiation emitted by tritium produces destructive radiolytic processes in the polymer networks. These processes can be studied by radiometric techniques using radioisotope labelled compounds or by spectrophotometrical methods by determining the spectral isotopic effects in the IR range. In this work, a method of preparation of polyacrylic acid labelled with tritium (T) and deuterium (D) in α) - positions is presented. The α - T polyacrylic acid has been obtained by radiopolymerization of 30% aqueous solution of acrylic acid which contains α-T sodium acrylate as tracer. The activity concentration was 1mCi/ml. The deuterium labelled polymer was obtained by radiopolymerization of 30% aqueous solution of α - D acrylic acid with an absorbed dose rate of 0.3 Mrad/h from a 60Co γ source. The integral absorbed dose was 0.4 Mrad at room temperature. The labelled monomers were synthesized by heterogeneous catalytic hydrogenation (Pd/C catalyst) of αBr acrylic acid in the presence of Cu 2+ ions as homopolymerization inhibitors. The brominated compound was obtained by reaction of addition of Br2 to the acrylic acid in chloroform solution. (authors)