EFFECT OF INTERMOLECULAR CROSS-LINKS ON DRAG REDUCTION BY POLYMER-SOLUTIONS

In this work we explore the effect of a cross-linking agent on the dra g reduction capability of hydroxypropyl guar and guar gum solutions in turbulent flow through horizontal pipes. The results show that the ad dition of a cross-linking agent (borax) to solutions with concentratio ns below those required for gel formation enhances drag reduction due to the increased dimensions of the macromolecules in the presence of i ntermolecular cross links. The flow-induced degradation of the polymer s is not appreciably affected by the addition of cross-linking agent.