Available online at www.pelagiaresearchlibrary.com Pelagia Research Library Advances in Applied Science Research, 2012, 3 (4):2128-2133 ISSN: 0976-8610 CODEN (USA): AASRFC 2128 Pelagia Research Library Effect of gamma radiation on thermal stability of PADC-American Acrylics detector Dipak Sinha 1* , Tokavi I.Chophi 1 and Toka Swu 2 1 Department of Chemistry, Nagaland University, Lumami-798627, Nagaland, India 2 Department of Chemistry, Pondichery University, Puducherry-605014, India _____________________________________________________________________________________________ ABSTRACT A comparative study on thermal properties of gamma irradiated PADC-American Acrylics track detector is done in dose range of 10 1 –10 6 Gy. TGA studies reveal that due to gamma exposure the thermal stability of the detector decreases at a dose higher than 10 4 Gy. It is also observed that the post-gamma mode of exposure of the detector has got more significant effect on thermal stability then the pre-gamma mode of exposure. Due to etching of the detector, thermal stability of the detector decreases drastically at a dose of 10 6 Gy. The weight loss by the detector upon heating is found to be endothermic in nature and takes place in the temperature range of around 375 0 C. However, due to gamma exposure, this endothermic transition takes place at a lower temperature of around 350 0 C. Chemical etching of the detector leads to further lowering of this endothermic transition. The amount of heat involves for the endothermic process of weight loss is found to be around 5.66 J/g for the pristine sample, whereas for irradiated sample of 10 6 Gy, it is found to be 20.95 J/g. Keywords : TGA,DTA, DSC, Gamma Dose _____________________________________________________________________________________________ INTRODUCTION Interaction of radiation with polymers lead to different structural modifications such as chain scission, chain aggregation, formation of double bonds and molecular emission, and consequently, many of their physico-chemical properties like optical, electrical, mechanical, chemical and track properties are modified [1-8]. In view of this, studies on application of radiation on polymeric materials are of great importance as they allow for desired improvements in polymer properties. Among the different studies on polymeric materials, thermal studies are one of the most useful as the different thermal properties of a polymer are strongly dependent on their internal structure of the polymer. Since exposure to radiation is known to be one of the major factors that change the structural properties of polymers, it was considered to be worthwhile to study the modifications of their thermal properties due to irradiation. A survey of the literature indicates that the thermal characterization of irradiated polymers have been studied by different authors [9-15]. However most of the authors have either studied polymers irradiated by heavy ions or by lower doses of gamma radiation. Keeping this in mind, the present paper presents details of thermal studies on gamma irradiated PADC-American detectors exposed to very high doses of gamma radiation (up to a dose of 10 6 Gy). In one of our earlier observations we have briefly reported [11] that due to gamma irradiation, the thermal stability of different polymers are significantly modified. Therefore, as a case study, in this present work a detailed study on modifications of thermal properties like its stability, exothermic and endothermic behaviour while loosing weight, ect. are presented for PADC-American Acrylics detector.