Study On Preparation And Properties Of Self-embrottling Cracking Decontaminant Based On PMMA-b-PMAA

Radioactive contaminants are produced inevitably in the nuclear decommissioning and nuclear incident response, which have tremendous harmfulness not only to the humans but also to the entire ecosystem, and its influence can reach hundreds of years to tens of thousands of years or even longer. Therefore, removing the radioactive pollution has become the focus of nuclear field and the current problem needed to research and solve. At the moment, physical decontamination and chemical decontamination is the main method for removal of radioactive contamination on device surface. Some problem have been solved in the practical application. However, there still exist some problems, such as the decontamination effect is not ideal, or many secondary waste radionuclide complexing agent as funct ional monomer . The structure of products was characterized by IR. The thickening mechanism and cross - linking mechanism were discussed. The influence of monomer ratios of MMA and MAA, fi lm thickness and different base material surface to embritt lement morphology was invest igated. The decontaminat ion efficiency of the self-embri ttling decontaminant was studied. Combining with the embri ttlement morphology, the research for embrit tlement mechanism of the self -embri ttling decontaminant was summarized. and waste liquid are produced. A self-embritt ling decontaminant was prepared which can be self -embrittlement cracking and achieve the effect of decontaminat ion after coating on a dirty surface. Through properly molecular design, poly (methyl methacrylate) -bpoly (methacrylic acid) diblock copolymers (PMMA-b-PMAA) were prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization in emulsion, using Methyl Methacrylate (MMA) and Methacrylic Mcid (MAA) as monomer, a water -soluble trithiocarbonate 3- (Benzylthiocarbonothio) Propionic Acid (BCPA) as RAFT reagent . The structure of products was characterized by IR and 1H NMR. The relat ive molecular weight and molecular weight distribution of products were measured by GPC. The thermal stability of products were studied using thermal analysis (TG and DSC) . The morphology and size of latex particles were measured by TEM. The effect of the feeds of RAFT reagent, reaction time and monomer ratios on polymerization products were investigated. A self-embritt ling decontaminant for removal of radioactive contamination on device surface was prepared, using the PMMA-b-PMAA diblock copolymers as binder, by adding cross-linker reagent and radionuclide complexing agent as funct ional monomer . The structure of products was characterized by IR. The thickening mechanism and cross - linking mechanism were discussed. The influence of monomer ratios of MMA and MAA, fi lm thickness and different base material surface to embritt lement morphology was invest igated. The decontaminat ion efficiency of the self-embri ttling decontaminant was studied. Combining with the embri ttlement morphology, the research for embrit tlement mechanism of the self -embri ttling decontaminant was summarized.