The development related to the effective degradation or recycling of polymeric material are of high priority in research because of solid waste removal problems in the environment and to establish sustainable conditions. Ionic liquids having low vapour pressure and other useful properties are finding increasing applications in the field of polymer science. In the present report, we describe the studies related to the plasticizing effect of simple 1-butyl-3-methyl-imidazolium bromide (an ionic liquid) on polyvinyl chloride. The admixtures of PVC and IL were subjected to heating (353-453 K) as a function of time (1-7 h). The resulting product stability was studied by TGA. Similar studies were carried out with PVA via glycolysis, i.e. in presence of ethylene glycol and products obtained were studied by TGA. Our results indicate that the addition of ionic liquid stabilizes the polyvinyl chloride and prevents liberation of HCl, while the polyvinyl alcohol gets degraded rapidly. These findings support the hypothesis of solubilization and degradation depending upon structural characteristics of polymeric molecules. The implications of these findings are discussed in terms of electrostatic, ion dipole and H-bonding interactions within polymer molecules influenced by thermal energy effects.