Polymeric surfactants for enhanced oil recovery. Part V: Prediction models for the effect of temperature and length of polyoxyethylene chain or hlb on surface and thermodynamic properties of some ethoxylated polymeric nonionics

Several equation models were investigated to find the relationship between temperature (T). number of ethylene oxide (EO) units (n) or the hydrophile-lipophile balance (HLB) and the surface and thermodynamic properties of some ethoxylated alkylphenol-formaldehyde polymeric nonionic surfactants. These properties include critical micelle concentration (CMC), free energy of micellization (ΔG_mic), surface tension at CMC (7_CMC), effectiveness (γ_CMC) and efficiency (pC₂₀) of surfactant to reduce the surface tension of water. The values of the ratio CMC/C_{2(π = 20)} were also considered. The linear multiple regression technique was employed to determine the parameters of the equations and to choose the best forms with the highest values of R² and F-ratio which reflect the goodness and the reliability of the fit.