可聴周波数域における各種熱可塑性樹脂の複素動的弾性率の測定

抄録

The frequency dependence of the complex dynamic moduli (Young's modulus and shear modulus) of various thermo-plastic resins has been measured in the frequency range of 1〜10^4 c/s at room temperature (20℃). The results of the measurement are as follows; 1) the frequency dependence of the complex moduli is generally small, 2) the mechanical loss factor tan δ is large with polypropylene, tetrafluoroethylene, trifluorochloroethylene, polyethylene and PMMA, 3) both large storage modulus E' and loss modulus E'' are large with PMMA, 4) the values of √&ltE'/ρ&gt of these resins are 1/3〜1/8 of those of metals such as duralumin and titanium, 5) the values of Poisson's ratio of these resins range from 0. 1 to 0. 4 (these values are much less than that of rubber of 0. 5). These results are discussed from the standpoint of the application of the plastics to acoustic and mechanical vibration systems. Methods for experiments are detailed to some extent.