抄録
(A)The ultrasonic velocities and elastic constants of linear polymers were measured by Bar-Walti's rotating plate method with impulse ultrasonic waves. (B)The linear polymers used are polystyrene, polymethyl-methacrylate, polyamide(Amilan), polyvinyl-acetate, and polyvinyl-chloride. (C)The frequencies from 450 kc. to 8Mc. /sec. were used. (D)No difference of elastic constants was found with polyvinyl-acetates of different polymerisation degrees from 6700 to 1150. (E)Elastic constants decrease with increasing plasticiser contents in the following systems:polyvinyl-acetate with dibutly-phthalate, and polyvinyl-chloride with dioctyl-phthalate.
