1972 年 21 巻 224 号 p. 397-400
The fibrin clots were prepared from bovine plasma and fibrinogen aqueous solution to which thrombin was added. The clots were gently compressed, thoroughly washed with distilled water, stretched by rolling, and formed into oriented films. Shear induced piezoelectricity was observed in such films, as well as those electrically oriented during the process of gelation.
The temperature dependence of both the piezoelectric strain-constant and stress-constant showed a marked dispersion at about 0°C. The dielectric and viscoelastic measurements also revealed two dispersions around 0°C (β) and -100°C (γ), respectively. In the β dispersion, the relaxation strength decreased, and the temperature for the maximum of loss increased with the decreasing moisture content. The relaxation may be due to the onset of the thermal motion in side-chains, which is hindered by the hydrogen-bonds formed between the adjacent molecules when the moisture content decreased. The γ dispersion is observed only in the thoroughly dessicated state and it may have been caused by the local motions of molecular chains. The presence of water appears to diminish the free volume necessary for the local motions.