NON-NEWTONIAN FLOW OF DILUTE POLYMETHACRYLIC ACID SOLUTIONS AT DIFFERENT DEGREES OF NEUTRALIZATION AND IONIC STRENGTHS

摘要

A careful experimental study of the gradient dependence of viscosity for dilute solutions of polymethacrylic acid (M 112,000) has been performed. Measurements have been made at six degrees of neutralization between 10 and 90 percent and ionic strengths between 0. 5.10-3 M and 5 . 10-3 M. The velocity gradient range covered is 2 - 71,000 sec-l. Isoionic dilution has been employed to permit linear extrapolation to zero concentration. As expected the gradient dependence is most pronounced when the polymer is highly charged and the ionic strength is low. The experimental results are mainly viewed in the light of theories concern¬ing the rigidity of the macromolecular coil.