DISSOLUTION EQUATION OF POLYMER

The dissolution of the polar polymer, polyacrylamide (PAM), in water i s studied kinetically. The rate of dissolution, S over dot, of PAM is determined by means of measuring the conductivity of water as dissolut ion of the polymer proceeds. The thickness of the swollen surface laye r, delta, and the rate of swelling, W over dot, are determined with th e aid of penetration and followed surface track by conductometric elec trode. A kinetic equation reflecting PAM dissolution in water is obtai ned directly as 2S over dot + W over dot = (D) over bar(s)/delta, wher e (D) over bar(s) is the average diffusion coefficient of solvent in p olymer and is shown to be true in cases of nonpolar as well as polar p olymers. (C) 1996 John Wiley & Sons, Inc.