SURFACE-ACTIVITY AND EMULSIFICATION PROPERTIES OF SURFACTANTS DERIVEDFROM NONYLPHENOL ETHOXYLATED, ETHYLENE-OXIDE AND CARBON-DIOXIDE

The synthesis of new water soluble nonylphenol poly(ethylene carbonate ) surfactants derived from nonylphenol ethoxylated (NP(EO)(10)), ethyl ene oxide (EO), and carbon dioxide was carried out in high yields in t he presence of K2SnO3 as a basic catalysts. Synthesis reactions were c arried out in a stainless-steel reactor at 175 degrees C at an initial pressure of 800 psi for a 24 h-period. Surfactants were characterized by FTIR, H-1- and C-13-NMR. The percentages of carbon dioxide incorpo ration obtained were between 5.8 and 10.9, depending on the starting m olar ratio of NP(EO)(10):EO:CO2. CMC values, as well as cloud points d ecreased with the molar ratio CO2/EO, indicating a reduction of hydrop hilic character of the surfactants due to the addition of carbonate gr oups, O-C(=O)-O, into the ethoxylated chains. Also, the area per molec ule at the interface increased when molar ratio CO2/EO increased, indi cating a two site anchoring model for both hydrophobic moieties, poly( ethylene carbonate) chain and nonylphenol. Finally, nonylphenol poly(e thylene carbonate) surfactants showed good emulsification properties f or stabilizing sunflower oil in water emulsions.