Evaluation of viscosity molecular weight constant (K), short range parameter (A) and long range parameter (B) of Dextran in polar solvents

The viscosity-molecular weight constant (K), the short range parameter (A) and long range parameter (B) have been evaluated in binary mixture of Dextr an of three different molecular weights in three different solvents i.e., d istilled water, 1(N) NaOH and 1(N) KOH, at temperatures ranging from 25 deg reesC to 50 degreesC. The study reveals that the viscosity-molecular weight constant (K) decreases with increase in temperature for polar solvents. Th e short range parameter(A) shows the same trend as shown by K and the long range parameter(B) exhibits no definite trend with the variation of tempera ture.