Solubilization, Micellization, and Phase Equilibria of Polyoxyethylene Derivatives of Dehydroabietic Acid

Article abstract of DOI:10.1021/j100449a024

Poly(oxyethylene)dehydroabietates (DeHAb(EtO)_n) with polyoxyethylene chains of 11 and 22 units have been synthesized.Phase diagrams for the systems DeHAb(EtO)11-decanol-H2O and DeHAb(EtO)22-decanol-H2O have been determined.In both systems a lamellar liquid crystalline phase is formed.The surfactants behave similarly to nonionic surfactants with an alkyl or alkyl/aryl hydrocarbon chain.The solubilization of dehydroabietinol (I), 1-octadecanol (II), decahydronaphthalene (III), decane (IV), and octadecane (V) was investigated at 60 deg C in solutions of DeHAb(EtO)22 and compared with a technical polyoxyethylene nonylphenol ether with 20 EtO units.The maximum solubilization in micellar solutions decreased in the order I > II > III > IV ca.V ca. 0 for both surfactants.These results can be conveniently correlated with the location of the solubilizates in the micelles as predicted on the basis of polarities and partial molar volumes.In all cases larger amounts were solubilized in DeHAb(EtO)22 than in the nonylphenol surfactant.This can be rationalized as a result of the lower cloud point of the DeHAb(EtO)22, which is probably due to the differences in the hydrocarbon moieties of the two surfactants.