ポリスチロール溶液での超音波速度とその温度変化について
Ultrasonic Velocity and its Temperature Dependence in the Polystyrene Solution

Akira Odashima, Junkichi Sohma
1952 Acoustical Science and Technology  
We 皿 easured the ultrasonic velocity ( frequency 444 kc ) in the polystyrene − benzene solution by the interferometer method . The molecular weight of the used polystyrene sample was about 446. 000 , First , the dependence of velocity on concentration was observed . We found that the velocity increased with increase of concentration in diluted solution up to the concentration of O . 03 gr / cc , in which the velocity attained 1339 m / sec , but ' in conGentrated solutions above that the
more » ... ve that the velocity was approximately . constant . This suggests that , also in tlle high frequency region there are two different states in high poly ・ mer solutions , as in dicated by static measurements of viscosi し y and speci 丘c volume . And the boundary concentration between these tWo states obtained by this measurement is of the same order of , magnitude as obtained fro皿 static ones . We calculated the velocity of this diluted solution by employing a model ana ! ogous to Eyring ' s free volume 皿 odel , and velocity values obtained are in good agreement with the experimental ones . We calculated the ad 量 abatic compressibility of this solution in various concentratiens from the velocity and density data。 Next , we observed the temperature dependence of velocity in concentrated solutions with various con 。 centration . 1皿 each ooncentration , the abrupt increasement of velocity in the neighbourhood of the melting point of benzene were observed . This suggests that the concentrated poly 皿 er . solution might have some transition region in this temperature region . § 1. 序
doi:10.20697/jasj.8.2_83 fatcat:2o67lt3vbzcahh5mrikbwy52q4