Effect of anionic surfactant upon the viscosity of polymer guar gum solutions

The reduced viscosity of polymer guar gum solutions containing a certain concentration of sodium dodecyl benzene sulfonate (SDBS) was measured. It has been found that the Huggins coefficient k(H) of polymer solutions is very sensitive to the concentration of the surfactant, c(SDBS), in solutions. If c(SDBS) is lower than CMC, the critical micelle concentration of SDBS, k(H) increases rapidly with C-SDBS. On the other hand, if C-SDBS is larger than CMC, k(H) decreases rapidly with C-SDBS. Comparatively, the intrinsic viscosity of polymer solution does not show a notable change with C-SDBS. The experimental results indicate that the interchain association of polymer guar gum in solution is greatly associated with SDBS interacted with polymer chains through hydrogen bonds. However, the effect of SDBS upon the intrachain association of polymer guar gum solution is negligible, presumably due to the fact that guar gum is a slightly stiffened random-coil chain polymer.