Abstract:

The static surface tension, salt resistance, acid resistance, metal corrosion, and detergency of alkyl diphenyl ether/alkyl benzene mixed sulfonates （denoted as DL-n, where n=3, 5 and 7; take n=3 as an example, it refers to the mass ratio of alkyl diphenyl ether in raw material is 30% while the mass ratio of alkyl benzene is 70%） were evaluated. The results of DL-n were compared with those of sodium dodecylbenzene sulfonate （LAS） and sodium dodecyldiphenyl ether disulfonate （MADS）. It was found that, among the DL-n series, LAS and MADS, LAS exhibited the lowest critical micelle concentration （cmc）, the lowest surface tension at cmc, and the worst acid resistance. The salt resistance and acid resistance of DL-n were improved as the alkyl diphenyl ether content in raw material was increased. There was no significant difference among the DL-n series in metal corrosiveness to duralumin alloy LY12-BC2, Z₃₀ grade 1 cast iron, and copper sheet, or in the detergency for artificial oil stains. The corrosiveness of DL-n to 45# steel and magnesium sheet was lower than that of LAS. The detergency of DL-n for anti-oxidation rust-preventive hydraulic oil and drawing oil decreased as the alkyl diphenyl ether content in raw material was increased. The DL-n series showed potential for use in processes with strong acidity and for industrial cleaning of 45# steel.

Key words: mixed sulfonates, salt tolerance, acid resistance, corrosiveness, cleaning power, industrial cleaning