Radiation effects on hydroxypropyl methylcellulose phthalate in aqueous system

水中におけるヒドロキシプロピルメチルセルロースフタル酸エステルの照射効果

Xu, L.*; Yue, Z.*; Wang, M.*; Zhai, M.*; 吉井 文男; 瀬古 典明; Peng, J.*; Wei, G.*; Li, J.*

Xu, L.*; Yue, Z.*; Wang, M.*; Zhai, M.*; Yoshii, Fumio; Seko, Noriaki; Peng, J.*; Wei, G.*; Li, J.*

水に対して不溶性のヒドロキシプロピルメチルセルロースのフタル酸エステルをナトリウム型に転化した後、ペースト状態で線照射することにより橋かけさせることに成功した。また、メチルビスアクリルアミド(MBA)やエチレングリコールジメタクリレート(EGDMA)などの橋かけ助剤を用いることで、MBAについては架橋後のゲルが剛直になり、EGDMAについては、より柔らかく、加工しやすい特性を有するゲルを作製できることがわかった。

A water insoluble cellulose derivative, hydroxypropyl methylcellulose phthalate (HPMCP) hydrogels, was converted to Na type to form hydrogel in paste-like status by radiation crosslinking. Mechanism for radiation crosslinking of cellulose-derivatives in paste-like status was discussed. Crosslinkers, i.e., methyl -bis-acrylamide (MBA) or ethyleneglycol dimethacrylate (EGDMA) has been used to decrease gelation dose (Dg) of synthesis HPMCP hydrogels and improve its mechanical properties. MBA was found to be more effective for accelerating the crosslinking of HPMCP than EGDMA. Swelling degree of HPMCP hydrogel in many kinds ofsalt solutions followed Hofmeister series, which is ubiquitous in polyelectrolyte hydrogel. Specific reswelling was observed in concentrated KF solution, implying a very strong F binding ability of benzyl group. The comprehensive results obtained in this study will be utilized on the design of HPMCP-based controlled release system.