Dielectric study on dynamics of electron-beam-induced gelation of hdroxypropylmethylcellulose (HPMC)

Morishita, Satoshi*; Umino, Yuya*; Kita, Rio*; Shinyashiki, Naoki*; Yagihara, Shin*; Furusawa, Kazuya*; Dobashi, Toshiaki*; Nagasawa, Naotsugu

Dielectric relaxation measurements were performed for the systems of hydroxypropylmethylcellulose (HPMC) in 1,4-dioxane and HPMC gel immersed in 1,4-dioxane. The HPMC gel was prepared by an electron beam irradiation for HPMC aqueous solution. Two relaxation processes were observed for both samples. Higher frequency process of each sample in the range of 300 kHz - 100 MHz was attributed to a chain motion of HPMC, while lower frequency process observed for the HPMC gel in the range 100 Hz - 300 kHz was significantly larger than the HPMC in dioxane. This observation indicates that DC conductivity due to the beam irradiation had a pronounced effect for the slower relaxation process.