Foaming properties of alcohol ethoxylates derived from natural products

Abstract

Alcohol ethoxylates (AEs) produced from natural products (palm oil and coconut oil) have been increasingly considered to replace NPEs (nonylphenol ethoxylates). In this work, the properties of fatty alcohol ethoxylates—C₁₂-₁₄EO₃, C₁₂-₁₄EO₅, C₁₂-₁₄EO₇, and C₁₂-₁₄EO₉—were studied and the results are compared to those from nonylphenol ethoxylates—NPE- 6 and NPE-9. The CMC, cloud point, contact angle, and gel range were studied. The foam characteristics were determined in terms of foamability and foam stability by using the simple shaking test, the Ross-Miles foam test, and pneumatic foam test. The results showed that the CMC slightly increased when the number of the ethylene oxide (EO) group increased. An increase in EO number resulted in an increase in cloud point temperature. The contact angle of 1 wt% surfactant aqueous solution on the nonpolar parafilm surface was found to increase from 38 to 53° with increasing the number of the EO group. In gel range experiment, the phase of these ethoxylates were observed at increasing concentration of surfactant solution which occurred the phase in order following; L₁ (micellar solution) —> H (hexagonal phase) -> L₂ Lamellar phase. Concentration of surfactant solution and the effect of the number of the EO group affected to the performance of foam of all studied methods. However, the high EO unit around 7 to 9 EO of fatty alcohol ethoxylates showed good foam performance when compared with nonylphenol ethoxylates.