Acoustic properties of ternary systems poly(vinyl chloride)-poly(vinyl butyral)-dibutyl phthalate

The effects of plasticizer on the propagation velocities of longitudinal and shear ultrasonic waves, their attenuation coefficients in the poly(vinyl chloride)-poly(vinyl butyral)-dibutyl phtalate (PVC-PVB-DVP) blend were studied. The most significant variations in the propagation velocity of longitudinal ultrasonic waves are observed for a dibutyl phtalate contents below 2 vol %. The concentration dependence of the propagation velocity of shear ultrasonic waves is characterized by a monotonic decrease in the velocity with increasing the dibutyl phtalate concentration in the system. The results of calculations indicate, that in the plasticozes concentration range below 5 vol % the value dynamic viscosity exceeds those in the PVC-PVB and PVB-DBP systems and is comparable with the values for the PVC-DBP system. Within the framework of the model of isotropic dielectric, theoretical estimations are obtained for dissipative energy losses, shear and bulk viscosity, relaxation time, and dimensions of the segment involved in the motion under the action of a force field.