MOLECULAR WEIGHT STUDIES ON THE GAMMA IRRADIATION DEGRADATION OF POLY(METHYLMETHACRYLATE) IN THE ABSENCE AND PRESENCE OF SULFANILAMIDE DERIVATIVES, PART I: TETRAOXALYLSULFANILAMIDE AND ITS COBALT (II) COMPLEX

Abstract

Protection of some poly (methylmethacrylate) samples against gamma rays has been investigated in the absence and presence of Tetraoxalylsulfanilamide and its Cobalt (II) complex. The pure PMMA (without additives), PMMA-Ligand and PMMA - Cobalt (II) complex composite samples were irradiated with gamma rays for different exposure doses (5, 15, 25, 35, 50, 75 and 100 KGy). Viscosity average molecular weight (Mv-values) and thin layer chromatographic measurements were carried out after each irradiation dose.The maximum protection against gamma ray is found when 3% of the organic ligand or its Cobalt (II) complex is used in the polymer matrix.The radiation chemical yield for chain scission (Gs) is calculated and has its lower values in the case of the organic ligand, which means that the protection is stronger in the case of the organic ligand than its Cobalt (II) complex. From TLC studies, it is noticed that both the Rf-values and polydispersity of the PMMA samples increase with increasing exposure dose.