No abstract

Ultrasonic absorption, velocity, adiabatic compressibility, relaxation time and relaxation amplitude measurements are reported on poly(vinyl chloride) (PVC) solution in tetrahydrofuran (THF) using pulsed ultrasonic apparatus operating at 2 MHz and 313 K. Results show a linear increase of velocity. density, viscosity, absorption coefficient, relaxation time and relaxation amplitude values with the increase of PVC concentration in THF. In contrast the compressibility decreases with increasing PVC concentration. This suggests interaction between PVC and THF molecules.

No abstract

No abstract

Ultrasonic velocity and isoentropic compressibility measurements are reported on aqueous solutions of polyethylenoxide of different molecular weights and different concentrations using pulsed ultrasonic apparatus operating at 2 MHz and 310 K. The data obtained as a function of concentration indicate the magnitude of the contribution due to relaxation of the backbone of the ethylene group. The results show a linear increase of density, velocity and viscosity values with increasing molecular weight and concentration of PEO. In contrast, the isoentropic compressibility decreases with increasing of molecular weight and concentration of PEO. A mathematical equation correlating isoentropic compressibility and molecular weight of the polymer is suggested. This was applied to the calculation of the molecular weight of unknown samples of PEO from their measured isoentropic compressibility; the results obtained agreed well with those obtained from osmometry.