1.高性能アミノ酸樹脂の開発と合成樹脂の物性 ペプチド固相合成法に準じ,アミノメチル及びクロロメチル化ポリスチレン樹脂を基体に,各種保護アミノ酸と擬アミノ酸を縮合導入したアミノ酸樹脂を30種合成した.アミノ酸導入量は約2〜3.7mmol/g-樹脂(導入率73〜100%)で疎水性アミノ酸ほど高導入率となったが,乾燥,湿潤時比重,含水率,IR,イオン交換容量の測定により,合成樹脂の物性を評価した.また,樹脂の酸,アルカリ浸漬,酸洗浄効果,再使用性を検討し,開発樹脂は耐久性を有する高性能樹脂であることを明かにした. 2.ウラン平衡吸着量と選択吸着機能 ウラン平衡吸着量はArg-,β-Ala-AMR樹脂では1gU/g-樹脂以上となり,樹脂の高性能化をほぼ達成した.また,吸着性に及ぼす各ウラニル塩の序列は,硝酸<臭素<酢酸<塩素<硫酸≪炭酸となり,炭酸種に極めて大きな吸着活性を認めた.プロトン付加した残基アミノ基が吸着の駆動力となるが,吸着等温式の解析,トリウムや重金属混合系からのマクロ分離,海水マトリックスからのウラン回収により,その選択吸着機能を確認した.今後,繊維状吸着剤への発展が望まれる. 3.ウラン同位体の分離濃縮挙動 樹脂接触による天然ウランの同位体分離濃縮挙動をバッチ法により追跡した.α線測定により各樹脂の^<234>U/^<238>U分離係数を決定したが,アミド結合型よりエステル結合型樹脂の濃縮効果が大きく,樹脂内アミノ酸の酸化還元作用が濃縮加速因子となることが示唆された.担持するアミノ酸と溶液,温度条件にもよるが,溶液内酸化還元平衡に較べ330倍,錯化法の8600倍の分離係数を示す樹脂もあった.^<235>U/^<238>U分離係数は,ICP-MS法では測定誤差が大きく,有意な評価を行えなかった.この他,海水浸漬ウランを樹脂接触し同位体分離傾向を認めたが,今後,高効率の多段接触分離システムへの適用が待たれる.
1. Synthesis of high efficient amino acid resins and the resin properties : We have synthesized 30 types of amino acid resin, introducing amino acid or imitative amino acids into poystirene resin according to the solid phase synthetic method of peptides. Amino acid contents introduced were estimated to be about 2-3.7 mmol/g-resin (introducing rates, 73-100%) and the resin properties were evaluated by the measurement of ion exchange capacity, water content, FT-IR and etc.. We alsoinvestigated a washing effect with acids, alkali soaking and repeated uses of the resins, and clarified that the developed resins were highly efficient and functinal ones.2. Collction capacity and selection function of the resins to uranium : We have practically performed a high functionalization of the resins, because they possessed the durability for use and large equilibrium adsorption amounts, e.g., above 1gU/g-resin in Arg-and beta -Ala-AMR resins. We have also recognized high adsorptive activity of the re sins toward cabonate species of uranium, and the adsorptive order of uranium salts was nitrate < bromide < acetate < chloride < sulfate carbonate.The protonated amino residue in the resin may behave as a driving force for adsorptions, and the selective adsorptive function was confirmed by the isoterm analysis for adsoption, macro separation from thorium and heavy metal mixtures, and uranium recovery from sea water matrixes. Thereafter, the development of the resin to fibrous adsorbent would be desirable.3. Separation and concentration behaviors of uranium isotopes : The separation and concentration behaviors of natural uranium isotopes were tracesd by contacting the resins using batch method. The separation factors of ^<234>U/^<238>U in each resin were determined by alpha -ray measurement. The ester type resins introduced amino acid by ester bonding into PSt resin showed larger concentration effect than that of amido-bonding types. It suggests that the oxidation -redox action of amino acid within the resin behaved as a acceleration factor for the concentration. Although this effect would depend upon amino acids introduced and solution and temparature conditions, some resing showed separation factors above 330 times comparing with that of the oxidation-redox equilbria in solution and above 8600 times against the complxation method. The factors of ^<235>U/^<238>U were measured by ICP-MS method. But, we could not perform wholly a meaning evaluation, due to large errors at the measurement. Besides, we recognized separation trends of the isotopes by soaking the resins in sea water. Hereafter, one might expect that amino acid resins would be applied to the separation system with high multistage contact.
研究課題/領域番号:08458121, 研究期間(年度):1996–1997
出典：「高性能アミノ酸樹脂を用いる炭酸ウラニルの捕集と同位体分離濃縮に関する研究」研究成果報告書 課題番号08458121 (KAKEN：科学研究費助成事業データベース（国立情報学研究所）) 本文データは著者版報告書より作成