Research Progress Of Radiation Shielding Materials And Preparation Of New Rare Earth/Polypropylene Composite Fibers

There are many traditional shielding materials,but relatively simple.For example,concrete can only meet the fixed reactor radiation shielding;Pure boron oxide shielding material can effectively absorb neutron radiation,however,with the passage of time,its shielding effect will be weakened;Lead-containing substances are more toxic;Bismuth material’s protective effect is also good,but its price is higher not suitable for large-scale production;Rare earth ray shielding material development is getting better and better,which has become the focus of the majority of researchers.In recent years,there have been more and more reports related to ray shielding materials.There are many improvements of the preparation methods and the replacement of new shielding components in order to improve the overall shielding performance of the material.Although they reported a lot,that are concentrated on one or several shielding materials,relatively one-sided.Based on previous research and the latest news,this paper aims to conduct a detailed,rational and systematic review of the shielding materials.On the basis of market research,we bought some typical radiation shielding materials for structural analysis,and finally made a comprehensive review to help buyers correctly identify the market of shielding materials.The results show that,the rare earth fiber has the best thermal stability and air permeability,however,its moisture permeability is the worst.The best moisture perme-ability is fabric of sliver fiber.The the mechanical properties of lead-free 3 rubber arethe best.In the UV absorption,the protection of stainless steel fiber fabric is relativelygood.After testing,the average lead equivalent of lead-containing rubbers and lead-freerubbers are 0.50 mmpb,that meet the standards of X-ray protective clothing.In the next part of this research,composite fibers blended with three kinds of rare earthes were more outstanding than fibers blended with single rare earth in X-ray shielding performance.But the dispersion of rare earth in polypropylene was poor,and the existing of rare earth lowered the melting point of polypropylene.Using silicon coupling agent as the modifier,the dispersion of the modified rare earth in PP matrix became good in nano size,and the mechanical properties of composite fibers were enhanced by the remarkable reduction of rare earth’ particle size.Using dopamine as the modifier,the particle size of rare earth also decreased observably,and the modified rare earth/PP nanocomposies were prepared.The composite fibers were produced by the melt spinning method and the meltblown method.Comparing with the melt spun composite fiber which was made by a single rare earth filling with PP,the composite fiber which was made by a variety of rare earth filling with PP had a better X-ray shielding performance.A variety of rare earth filled with the PP that had little effect on the thermal stability.The addition of rare earth reduces the melting point of polypropylene.The mechanical properties of composite fiber which was produced by single rare earth filling with PP are bettert than that made by a variety of rare earth filling with PP.The composite nonwoven fabric was produced by meltblown.And the results is same as the melt spinning.The experiement indicated that X-ray shielding properties were reinforced as the addition of rare earth increased.