ポリビニルアルコール水溶液の超音波領域におけるレオロジー的研究
スポンサーリンク
概要
- 論文の詳細を見る
We reported previously some results of ultrasonic investigations of aqueous solutions of polyvinyl alcohol in the mega cycle region^1). In the present experiment we have attempted to obtain ultrasonic data on the solutions over a wider range of frequencies. An apparatus has been constructed for the measurement of ultrasonic velocity and absorption by means of the pulse technique, which is similar in principle to that of Pinkerton,^<1)2)> and which covers 1〜100 Mc/sec region. For the calibration of the apparatus the ultrasonic absorption coefficient,α, of pure water has been measured by this apparatus, and the obtainedαvs. temperature curve have nearly coincided with that of Pinkerton.^2) The two samples of polyvinyl alcohol used were the same as those reported in the preceding paper^1). The average molecular weight was 8.0×10^4 for the perfectly-saponified PVA sample and about 9×10^4 for the partly-saponified sample, and the amount of residual acetate group of the latter is 12 mol%. The sound Velocity and absorption were measured for 5 and 10 wt% solutions of the two samples. The temperature was varied within the range of 3〜70℃. The frequency ranged 5〜45 Mc/sec. The velocity versus temperature curve has a peak, as seen in pure water, but the peak is found to shift to lower temperature side and upwards with increase of concentration for both samples. The ultrasonic absorption of solutions of partly saponified sample is found to be larger than that of perfectly-saponified sample at the same concentration. The presence of two relaxation mechanisms has been found at these temperature and frequency region. For the solutions of two relaxation mechanisms has been found at these temperature and frequency region. For the solutions of perfectly-saponified sample the following two mechanisms are found : one whose relaxation timeτ_1 is about 5×10^<-9> sec at 12℃ and the other whose relaxation timeτ_2, is about 5×10<-9> sec at 40℃. The solution of partly-saponified sample have a similar behavior. The activation energy obtained from the temperature dependence ofτ_2 is about 4kcal /mole for both samples, and that for τ_1 is of the order of /mole. The value of M_2/ω, where M_2 is the imaginary part of the longitudinal wave modulus and ω the angular frequency has been found to be of the order of 0.1 poise.
- 社団法人日本材料学会の論文
- 1966-05-15
著者
関連論文
- 光増感によるルミノールの化学発光
- 水溶液中での個別イオンの諸性質
- 癌蛍光診断薬としてのHAT-D01の光物理化学的特性
- ポリビニルアルコール水溶液の超音波領域におけるレオロジー的研究
- 共有結合でつないだポルフィリンダイマーの物理化学的特性
- 水 : この普遍的且つ特異な液体
- 理科教科書の問題 (教科書についての見解二)
- 戰争体験の思想化 : 一人の戦後派の回想 (戦争体験をどう生かすかIII)
- ポリビニルアルコール水溶液の超音波音速ならびに吸収 : 高分子のレオロジー
- 尿素を添加した寒天水溶液ゲルのレオロジー的研究
- 粘度の自由容積理論について
- 溶液論の最近の動向 (高分子物性における最近の動向)