Use of acoustic methods for the determination of the absorbed dose and thermosetting qualities of oriented polymers modified by ionizing radiation

Based on the theory of solid matter deformation and taking into consideration the specifity of propagation of ultrasonic waves in polymers, the acoustic nondestructive method has been chosen for controlling radiation-curing of oriented polymers, mainly polyolefins and their compositions, used as thermosetting materials. The applied method allows to gain certain information about the exploitation characteristics of these materials. The correlation relationships of propagation velocities of flexural ultrasonic waves initiated in the material at a frequency of 60 kHt by piezo transducers-concentrators with exponential waveguides and point contact have been established. This permits the determination of the dose of ionizing radiation absorbed by the material, the content of fillers in the irradiated material, as well as the evaluation of the thermosetting forces or the internal stresses.