Properties of branched alcohol polyoxyethylene ether carboxylates

Abstract

A novel anionic surfactant alcohol polyoxyethylene ether carboxylates with three branched chains (A13EC5-Na, A13EC7-Na) were studied in the paper. Their surface properties were investigated by surface tension and dynamic surface tension. It was found that branched surfactants showed lower surface tension, which can decrease the surface tension of water to around 27 mN/m. The critical micelle concentration (CMC) of A13EC5-Na is lower than that of A13EC7-Na. What's more, A13EC5-Na molecules can adsorb to the surface faster than A13EC7-Na. The wetting abilities, emulsifying capacities, foam ability and detergency of branched surfactant aqueous solutions were studied in contrast to that of linear surfactants. The wetting ability of A13EC5-Na is better than that of A13EC7-Na. Compared with linear alcohol polyoxyethylene ether carboxylates (A12EC5-Na, A12EC7-Na), branched surfactants exhibit preferable wetting ability. Broadly speaking, the emulsifying capacities of branched surfactants for liquid paraffin and soybean oil are relatively good than that of linear surfactants. When the hydrophobic chains are the same, the emulsifying capacities of surfactants with smaller oxyethene (EO) number for liquid paraffin and soybean oil perform better. The foam ability and foam stability of A12EC5-Na are the best. The foam ability of A13EC7-Na is better, but the foam stability is poor. In short, the foam stability of branched surfactants is inferior to that of linear surfactants. The detergency performance of linear and branched surfactants to sebum cloth performs the best compared with protein stain and carbon black cloth. The detergency effect of A12EC7-Na for sebum cloth is the best, A13EC7-Na takes second place and A13EC5-Na is the worst. Branched surfactants are expected to become a promising product for their outstanding wetting abilities and emulsifying capacities and their better foam ability and detergency.