THE SPECIFIC VISCOSITY OF PARTIALLY HYDROLYZED POLYACRYLAMIDE SOLUTIONS - EFFECTS OF DEGREE OF HYDROLYSIS, MOLECULAR-WEIGHT, SOLVENT QUALITY AND TEMPERATURE
J. Sukpisan et al., THE SPECIFIC VISCOSITY OF PARTIALLY HYDROLYZED POLYACRYLAMIDE SOLUTIONS - EFFECTS OF DEGREE OF HYDROLYSIS, MOLECULAR-WEIGHT, SOLVENT QUALITY AND TEMPERATURE, Journal of polymer science. Part B, Polymer physics, 36(5), 1998, pp. 743-753
The dependences of the specific viscosity of several polyelectrolytes
on poly electrolyte concentration, salt concentration or solution ioni
c strength, solution pH value, solvent quality, and solution temperatu
re were systematically investigated. We found that the specific viscos
ity obeys a more general relation: eta(sp) = Ac-p(2)/(c(p) + 2C(s))(3/
2) + B, where eta(sp) is the polyelectrolyte specific viscosity, c(p)
and c(s) are polymer and salt concentrations, respectively. The prefac
tor A depends critically on chain size, solvent quality, and temperatu
re in qualitative agreement with the theory proposed by Rabin et al. T
he intercept B is nonzero or less than zero in polyelectrolyte solutio
ns with low ionic strength. When a sufficient amount of salt has been
added, B is reduced to zero and we recover the Rabin et al.'s relation
. The physical interpretation for the intercept B is that it represent
s the inverse of the strength of electrostatic interaction between a p
olyion and counterions, in quantitative agreement with the well-known
emperical Fuoss's relation. Furthermore, the existence of nonzero B al
lows us to calculate the condition for the maximum in the reduced visc
osity-polymer concentration curve in a polyelectrolyte solution system
without salt. (C) 1998 John Wiley & Sons, Inc.