Is reduced viscosity a polyelectrolyte effect in partially hydrolyzed polyacrylamide?

Various reduced viscosity measurement tests were conducted to characterize the viscosity behaviour of partially hydrolyzed polyacrylamide. Experiments show a polyelectrolyte effect when reduced viscosity is plotted against polymer concentration. The reduced viscosity is rising in salt free solution due to dilution.

What is the rheological behaviour of aqueous solutions of polyacrylamide?

Rheological behaviour of aqueous solutions of polyacrylamide depicting the effect of temperature and concentration in the range of 5–45 °C and 0.25–0.6% wt/vol, respectively, was studied. Based on the observed experimental data, the following conclusions are drawn:

What is partially hydrolyzed polyacrylamide?

This form of HPAM is referred to as partially hydrolyzed polyacrylamide. Second, during the polymerization process, acrylamide monomers can be copolymerized with acrylate monomers to form HPAM. This form of HPAM is referred to as being a copolymer of acrylamide and acrylate.

What is the acceleration effect of polyacrylamide hydrolysis?

(ii) Constant pH. In Figure 14 some predictions of hydrolysis kinetics of polyacrylamide are given for different constant pH and three values of Z. These simulations correspond to a polymer concentration of 8 x 10-4gcm-3 and T= 80. The acceleration effect is significant for pH up to 7 and becomes negligible for higher pH.

How does pH affect polyacrylamide hydrolysis?

Muller et al. , proposed that polyacrylamides would hydrolyze under slightly acidic conditions (pH = 4), and reported that the molecular weight of the polymer remained relatively stable during hydrolysis. Thomas et al. , investigated the effects of different pH conditions and reaction times on the hydrolysis process.

Does hydrolyzed polyacrylamide have a pH dependence?

They discovered that the viscosity of hydrolyzed polyacrylamide exhibits pH dependence as characterized by transition zones (at pH = 3 and pH = 6), where the viscosity suddenly changes. This is because the hydrogen ions adsorb and dissociate from the carboxyl functional groups, a discovery which has significant application potential , .