Effect of Additives upon the Phase Transition Temperature of α,ω-(2-Hydroxyethoxy) Oligo(propylene oxide) in Aqueous Solutions

*The influence of various additives, like salts, alkohols, surfactants and water-miscible organic solvents, upon the cloud point of α, ω - (2-hydroxyethoxy) oligo(propylene oxide) in aqueous solutions was investigated for the first time. The results showed that NaH 2 PO 4 , NaCl, NaBr, NaI, 1-butanol, ethylene glycol and dimethylsulfoxide decreased the cloud point, while 1,2-propylene glycol, sodium dodecylsulfate, nonylphenyl ethoxylated with 9 moles of ethylene oxide and dioxane increased it. Addition of N,N-dimethylformamide practically had no influence upon the cloud point on the concentration interval investigated. The LCST of α, ω - (2-hydroxyethoxy) oligo(propylene oxide) in aqueous solution was also determined and it was found equal to 19°C.