Effects of Polymer Additives on Dynamic Interfacial Tension Behaviour of Acidic Oils against Alkaline Solutions

In this study, we have investigated the interfacial tension(IFT) lowering potential of arange of caustic solutions which were thickened with polymers. Two polymers, namely, polyvinyl alcohol (PVA) and polyacrylamide (PAM) were used. The dynamic IFT of caustic, polymer and caustic-polymer solutions were measured using the spinning drop tensiometer. The oleic phase consisted of 10 mM linoleic acid in light paraffin oil (acid number of 0.56 mg KOH/g oil). Thelowest IFT values were obtained at 12.5 mM NaOH. The polymers on their own were found to possess a significant interfacial activity compared to water alone. However, the addition of the polymeric material to the caustic solution produced only a marginal reduction in dynamic IFT at early contact time and also poduced characteristic IFT minima at all caustic concentrations. Beyond the minimum, the increase in IFT at longer contact times was more pronounced in the presence of polymer.