Ultrasonic velocity studies and allied parameters of poly(4-4′-cyclohexylidene-R,R′-diphenylene diphenyl methane-4-4′-disulfonate) solutions at 30°C

Isentropic compressibility, internal pressure, solvation number and free volume of poly(4,4′-cyclohexylidene-R,R′-diphenylene diphenyl methane-4,4′-disulfonates) (RH, RCH3) in chloroform, 1,2-dichloroethane, tetrahydrofuran (THF) and 1,4-dioxane (DO) at 30°C have been evaluated from measurements of sound velocity (3 MHz), density and viscosity of these solutions. The results have been interpreted in light of polymer–solvent and polymer–polymer interactions. The structural change has been found above 1.5 g/dl concentration, and predominant solvating tendency is observed in THF and DO systems indicating observed structural arrangement due to decrease in entropy of the system.