Dilute solution behaviour of partially hydrolysed polyacrylamide

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-fareast-font-family:"dejavu="" sans";="" mso-bidi-font-family:mangal;mso-bidi-theme-font:minor-bidi;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Flow behaviour of partially hydrolysed polyacrylamide (PHPA) is studied in aqueous and in ethylene glycol-water, dimethyl formamide-water binary solvents At low concentrations (100-1000 ppm) reduced viscosity (<i>ή_sp</i>/c) increases with decrease of concentration of the polymer. It obeys Fuoss plot, i.e,. c/<i>ή</i>_sp linearly depends on the square root of concentratijon (√C). However, In presence of Na⁺ reduced viscosity, <i>ή</i>_sp/c) of PHPA polymer is a linear function of concentration. The solution viscosity exhibits a substantial shear thinning effect in all the three solvents. Shear thinning behaviour diminishes on increase of salt concentration producing Newtonia behaviour (1-40 s^-1). Dilute solution of PHPA degrades when stored for a prolonged period. This aging behaviour can be prevented by using 300 ppm of antimicrobial agent such as monoethanolamine, diethanolamine and triethanolamine.</span>