Journal of Applied Polymer Science, Vol.97, No.2, 527-531, 2005
Rheological kinetics of acrylonitrile-acrylamide copolymer solutions in dimethyl formamide
Viscosity behavior of dimethyl formamide solutions of acrylonitrile-acrylamide copolymer is discussed. The rheological kinetics of the solutions was studied for contrast. It is shown that the solutions behave the same as Newtonian flow as the rotor speed goes beyond 6 revolutions min(-1). With an increase of temperature, the apparent viscosity of acrylonitrile-acrylamide copolymer solutions shows a decreasing trend. The changes of the apparent flow-activation energy of solutions calculated by Arrhenius equation become less prominent along with the changes of the molecular weight of acrylonitrile-acrylamide copolymers. The apparent flow-activation energy of the copolymer solutions increases continuously with an increase of copolymer concentration. The viscosity of copolymer solutions decreases continuously at concentrations of KCI and NaCl up to 0.02 mol L-1 and then increases. The apparent flow-activation energy of acrylonitrile-acrylamide copolymer solutions shows an obvious trend of decrease with addition of alkali salts and the changes of the apparent flow-activation energy of solutions containing NaCl are more prominent than those of solutions containing KCI. (c) 2005 Wiley Periodicals, Inc.