RADIATION EFFECTS ON THE PROPERTIES OF A POLYURETHANE/EPOXY GRAFT INTERPENETRATING POLYMER NETWORK

摘要

The toughening effects of a castor oil based polyurethane on an epoxy matrix, byrnmeans of an interpenetrating network (IPN) was investigated. In addition, the radiationrneffects of two PU/EP graft-IPNs, 19/81 and 27/73 PU/EP graft-IPNs, were examined sornthat possible application of these materials in the fabrication of containers to storernradioactive waste over long periods of time could be considered.rnThe polyurethane/epoxy graft-IPN was made by a sequential method ofrnsynthesis, in which the polyurethane prepolymer was prepared before the addition of thernepoxy resin and crosslinker. The PU/EP graft-IPN specimens were subjected to severalrndoses of radiation that ranged from 0.11 Mgy to 3.0 Mgy, using the SLOWPOKE-2rnnuclear reactor at Royal Military College of Canada (RMC). The irradiated andrnunirradiated IPN samples were then subjected to a battery of chemical and mechanicalrntests to determine the effects of radiation.rnBased on the observations from the chemical and mechanical tests, it has beenrnestablished that the 19/81 PU/EP graft-IPN is suitable for applications in radiationrnenvironments below a dose of 1.5 Mgy. The 27/73 PU/EP graft-IPN is unsuitable forrnradiation applications at low doses, however it shows a noticeable increase in chemicalrnand mechanical properties with increasing accumulated dose. Past work at RMC hasrnshown the beneficial properties of a ThOrnThO2 filler within the radioactive waste container.rnWith regard to the design of the disposal containers, with the aid of aThOrnaThO2 filler, it is thernopinion from the present work that the graft-IPNs could potentially be used in thernfabrication of containers to store low and intermediate level radioactive waste, as well asrnspent nuclear fuel and high level radioactive waste.