ABSTRACT
The ultrasonic method used a few times for the characterization of polymer mate rials is indicated in some literature reviews (1^0, studies (5-8), and reports on the progress in this technique (9). Taking into consideration the rapid development in the investigation of multiblock copoly[ester-Z?-ether]s and different multiblock copolymers using high-frequency techniques such as dielectric spectroscopy ( 10, 11) and electron spin resonance (12,13), it is reasonable to supplement these results with ultrasonic tests.
