Study On Preparation And Properties Of SiO₂/P?MMA-co-MAA? Self-embrittling Detergents

The removal of radionuclide pollution is a key issue in nuclear decommissioning and response to various nuclear emergency incidents.The major categories of decontamination technologies can be classified into physical methods and chemical methods.At present,strippable film decontamination and self-embrittling decontamination have gradually become the hot spot of surface radioactive decontamination because of its easy operation,wide applicability and simple waste post treatment.However,in practical applications,self-embrittling detergents produce ammonia,resulting in environmental unfriendliness.In order to improve this problem,in this paper,a series of self-embrittling SiO₂/P?MMA-co-MAA?detergentswerepreparedbyblendingmethodandin-situ polymerization,and their properties were studied.Preparation of SiO₂/P?MMA-co-MAA?self-embrittling detergents by blending method.Preparation of methyl methacrylate-methacrylic acid random copolymer[P?MMA-co-MAA?]emulsion based on emulsion polymerization.By adding silane coupling agent KH560 modified silica powder,SiO₂/P?MMA-co-MAA?decontaminationagentwithself-embrittling peeling property and detergency performance was prepared by high shear blending.The structure and properties of the composite emulsion were characterized and analyzed by infrared spectroscopy?FTIR?,thermogravimetry?TG?,X-ray diffraction?XRD?and scanning electron microscopy?SEM?.The effect of silica content,coating thickness,and substrate type on the self-embrittlement appearance of the detergent was investigated.The results show that the addition of modified nano-SiO₂ changes the aggregation structure of P?MMA-co-MAA?,which changes the self-embrittlement of P?MMA-co-MAA?emulsion.The main manifestations are as follows:With the increase of nano-SiO₂ content,the chip has a tendency to become larger.At the same time,the shrinkage and curl of the chip is more obvious,and the self-embrittlement stripping performanceof P?MMA-co-MAA?isimproved.This propertyhas advantages in removing radioactive waste from the surface of the equipment;at the same time,the size of the chips increases with the increase of the silica content and the coating thickness;The self-embrittling morphologies of decontamination agents on the surface of different types of substrate is also different.The self-embrittling morphologies are also different.Overall,the decontamination rate of surface loose radioactive contaminants has reached more than 97%.Preparation of SiO₂/P?MMA-co-MAA?by in situ polymerization self-embrittling detergent.with silane coupling agent KH570 modified silica and methyl methacrylate?MMA?of monomer,methyl methacrylate monomer?MAA?preparationofSiO₂/P?MMA-co-MAA?composite emulsionbyin-situpolymerizationmethod.Aselfembrittlement decontamination agent was obtained by adding sodium hydroxide solution to adjust the viscosity.The structure of composite emulsion was studied by FTIR and TEM.The results show that the modified silicon dioxide reacts with the monomer,and the latex particles form a core-shell structure with silicon dioxide as the core and P?MMA-co-MAA?as the shell.XRD analysis shows that the addition of silicon dioxide reduces the crystallization of the composite system;The SEM and AFM tests show that silicon dioxide increases the roughness of the coating and influences the brittle performance.Through the discussion of the monomer ratio,dosage of silica,substrate types on brittle morphology influence,the size of chips varies with the ratio of m?MMA?:m?MAA?,when m?MMA?:m?MAA?=5:1,The self-embrittlement performance of the detergent is better and the size of brittle chip is more conducive to mechanical collection;with the increase of the content of nano-silica,chips size becomes larger;Detergents can occur self-embrittling peeling on glass,tabletop,stainless steel substrate surface.The decontamination rate of the detergent is over 97%for loose radioactive contamination on the surface of glass,tabletop and stainless steel.