電子線グラフト重合法による製塩用新規イオン交換膜の開発,4; ナイロン6製フィルムを基材とした陽イオン交換膜の高分子構造

Development of novel ion-exchange membranes for electrodialysis of seawater by electron-beam-induced graft polymerization, 4; Polymeric structures of cation-exchange membranes based on nylon-6 film

宮澤 忠士*; 浅利 勇紀*; 三好 和義*; 梅野 太輔*; 斎藤 恭一*; 永谷 剛*; 吉川 直人*; 元川 竜平   ; 小泉 智*

Miyazawa, Tadashi*; Asari, Yuki*; Miyoshi, Kazuyoshi*; Umeno, Daisuke*; Saito, Kyoichi*; Nagatani, Takeshi*; Yoshikawa, Naohito*; Motokawa, Ryuhei; Koizumi, Satoshi*

Cation-exchange membranes containing a sulfonic acid group were prepared by electron-beam-induced graft polymerization of sodiumstyrene sulfonate (SSS) onto a nylon-6 film with a thickness of 25 m. The lamella sizes and lamella-to-lamella intervals of theresultant cation-exchange membranes (SSS membranes) were evaluated by X-ray diffraction (XRD) analysis and small-angle neutron scattering (SANS), respectively. With increasing degrees of grafting, the lamella size decreased, whereas the lamella-to-lamella intervalincreased. This can be explained by that the poly-SSS chain grafted to the periphery of the lamella of nylon 6 partially destroys the lamellaand invades the amorphous domain among the lamella. The SSS membrane with a degree of grafting of 150% exhibited a similarperformance in the electrodialysis of 0.5 M sodium chloride as a current cation-exchange membrane and possessed the lamella sizesand lamella-to-lamella intervals of 7.6 and 13 nm, respectively.