He jishu (Jun 2022)
Radiation protection performance and positron lifetime of nano Y2O3/epoxy resin composites
Abstract
BackgroundTraditional shielding X/γ ray materials are generally lead or lead containing materials, which have the disadvantages of high toxicity, heavy weight, difficult molding and high price. Polymer composite materials are considered to be new materials that can effectively protect against nuclear radiation in the future. Epoxy resin (EP) as a base material has many advantages, such as corrosion resistance, good mechanical properties, strong wear resistance, excellent insulation, and stronger radiation resistance, while rare earth materials have a better shielding effect on γ-rays in the 20~88 keV energy region, and can make up for the weak absorption zone of lead.PurposeThis study aims to verify the shielding performance of nano Yttrium trioxide/epoxy resin composites (Y2O3/EP) against X/γ rays.MethodsFirst of all, Y2O3/epoxy resin radiation protection materials with different yttrium oxide contents were prepared by filling Y2O3 into EP. Then, the positron lifetime spectrum analysis combined with X-ray diffraction (XRD), scanning electron microscopy (SEM) and other methods were employed to study the microstructure of the material whilst the thermogravimetric analysis and differential scanning calorimeter (DSC) were applied to analyzing the thermal stability of the material, and Vickers hardness tester and universal tensile machine were used to test the mechanical properties of the material. Finally, the Monte Carlo N Particle Transport Code (MCNP) was applied to the simulation calculation of the radiation protection performance of the these samples.ResultsTesting results show that Y2O3 filled with epoxy resin can improve the thermal stability, hardness and Young's modulus of the composite material, but reduce the tensile strength. In the X/γ ray energy range of 20~1 332 keV, the shielding effect of 40% Y2O3/EP composite is 2%~10% of that of pure Pb under the same material thickness, and the shielding effect of 40% Y2O3/EP composite is 15%~66% of that of pure Pb under the same mass.ConclusionsAlthough the shielding effect of Y2O3/EP composite is worse than that of pure lead, it can meet the shielding requirements at X/γ low-energy radiation region with capability to replace lead or lead containing materials as radiation shielding materials.
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