Viscosity studies of polyvinyl alcohol (PVA, Mw = 1,25,000) in solvent distilled water and aqueous solution of urea

Abstract

Reduced viscosity (ηsp/C) and inherent viscosity ln (ηrel/C) of PVA (Mw = 1,25,000) has been calculated by measuring the flow time of polymer solution in solvents like distilled water and 4M Urea at six different tempratures 25° C, 30° C, 35° C, 40° C, 45° C, and 50° C. From exptrapolation of curve (/C) versus C and (ln /C) versus C, thermoviscosity parameters like Huggins’ Constrant (KHl), Kraemer's constant (KHll) and viscosity concentration co-efficient (a2) have been estimated. In aqueous solution (PVA in distilled water), Huggins' relation does not hold good. So a2 = .201[h]2.28 is used; but in aqueous Urea (PVA in 4M Urea), Huggins' relation holds good. Also η =KMα and value of a more for 4M Urea i.e aqueous Urea is better solvent for PVA than distilled water.