Effect of Polymers on the Cloud Point of Dodecyl-polyoxyethylene Polyoxypropylene Ether Nonionic Surfactants

The effects of poly(ethylene glycols) with different molecular weight (PEG1000, PEG2000, PEG6000) and polyvinylpyrrolidone with different polymerization degree (PVP-K30, PVP-K90) on the cloud point of nonionic surfactant dodecyl polyoxyethylene polyoxy propylene ether C12H25O(EO)m(PO)nH (LS36,m=3, n=6; LS45,m=4, n=5; LS54,m=5, n=4) were studied in the paper. It is found that a higher polymer concentration can result in a significant decrease on the cloud point of the aqueous surfactant solutions because of the formation of corona-shaped intra-chain micelles which indicate that the micelle-micelle interaction is attractive and can be expected to facilitate collisions among the micelles, as well as a slightly increasing at a lower PVP concentration because of the effects of viscosity, charge, and interaction between the polymer and surfactant.