Preparation And Performance Study Of Modified Nano-samarium Bismuth Vinyl Ester Composite Shielding Material

Since the industrial revolution,the consumption of fossil fuels has increased unprecedentedly,and the development of clean and sustainable nuclear energy is crucial.The application of nuclear energy can generate ionizing radiation,mainly includingα/βParticlesγPhotons and neutrons.Where,γPhotons and neutrons have strong penetration,long range,and difficult shielding.Effective protective measures must be taken.aboutγFor photon protection,materials with high atomic numbers,such as heavy metal elements（Pb,Bi,etc.）and their compounds,are preferred.Neutron protection mainly relies on light nuclear elements（H,Li,C,etc.）and elements with large thermal neutron absorption cross sections（B,Cd,Sm,Gd,etc.）,which slow down and absorb neutrons,respectively.In the face of complex radiation environments and harsh operating environments,such as mobile nuclear devices and aircraft,protective materials must not only take into account the shielding of mixed radiation fields,but also have excellent physical and chemical properties,thermal and mechanical properties.Traditional shielding materials with a single shielding component and poor usability are no longer suitable,and composite materials filled with two or more different shielding functional fillers have become a development trend.For composite shielding materials,the selection of shielding components and matrix is particularly critical.The shielding component mainly determines the shielding performance of the material,while the matrix mainly determines the use performance of the material.Therefore,this article evaluates the protective performance of shielding filler combinations through simulation calculation software to obtain the most suitable filler combination,and then modifies the surface of the filler,eventually blending it with vinyl ester resin with better comprehensive performance to prepare efficient,lightweight,high-strength,economical,and easy to prepare hybrid radiation shielding materials,providing a reference scheme for the new generation of shielding materials.The main work of this article is as follows:（1）Simulation calculation and screening of shielding filler combinations.Using simulation software such as FLUKA to evaluate the shielding performance of shielding filler combinations and composite materials,the data shows a high degree of consistency between the simulation and theoretical calculation results.The photon and neutron shielding properties of the net filler combination and the vinyl ester composite were compared,and based on the shielding data,physical and chemical properties and cost factors of the filler,Sm₂O₃ and Bi₂O₃were selected as the shielding reinforcing fillers of the vinyl ester resin.（2）Modification and characterization of shielding filler combinations.Selecting KH-570whose organic group is similar to epoxy vinyl ester resin to modify the surface of Sm₂O₃ and Bi₂O₃ inorganic nanoparticles to obtain M-Sm₂O₃ and M-Bi₂O₃.The best modification conditions for Sm₂O₃ are 80℃,3 h and 100 wt%;the best modification conditions for Bi₂O₃are 80℃,4 h and 10 wt%.Based on the characterization results of FT-IR,XPS,TG and TEM,it can be seen that KH-570 has successfully covered the surface of two kinds of inorganic nanoparticles,the modification effect of M-Bi₂O₃ particles is better than that of M-Sm₂O₃,and the modified inorganic nanoparticles dispersion in organic media is more uniform and dispersion stability is improved.（3）Preparation and properties of oxirene ester composite shielding materials.MSBV was prepared using M-Sm₂O₃ and M-Bi₂O₃ as mixed radiation shielding fillers and vinyl ester resin as matrix.The effects of filler modification and content on the properties of composite materials were investigated.MSBV-2 doped with 20 wt%modified filler exhibited better thermal stability and stronger mechanical properties than SBV-2 doped with 20 wt%unmodified filler;with the increase of modified filler content,the thermal stability of the composite material gradually improved,and the overall mechanical properties showed a downward trend.When the filler was doped to 40 wt%,the mechanical properties of MSBV-4 dropped sharply;the gamma and thermal neutron shielding properties of the composite material were compared with those of The pure resin has been significantly improved.