ROLE OF IONIC SPECIES AND VALENCY ON THE VISCOELASTIC PROPERTIES OF PARTIALLY HYDROLYZED POLYACRYLAMIDE SOLUTIONS

The effects of ionic species and valency on the viscoelastic propertie s of partially hydrolyzed polyacrylamide solutions were examined. Two viscoelastic parameters were considered, i.e., average relaxation time , lambda(M)0 and steady state compliance, Je0. Both these parameters a re independent of ionic species of monovalent salts. However, lambda(M )0 decreases with increasing salt concentrations. Divalent salts reduc e the values of lambda(M)0 by as much as 10 times. On the other hand, Je0 is independent of salt concentrations and valency. The effects of monovalent salt on three different polyacrylamide samples of varying d egree of hydrolysis and MW were also examined.