Synthesis and Some Surface Active Properties of Fatty Derivatives of Propane Sultone. III.

Fatty Alcohol and Fatty Acid Derivatives

Abstract

Surfactants (R_iOC₃H₆SO₃Na, R_iCOOC₃H₆SO₃Na) having propane sulfonate group were prepared from fatty alcohols (C₁₀C₁₈) and fatty acids (C₁₀C₁₈).
Surface active properties of their aqueous solutions were examined on surface tension, foaming power, foam stability and CMC at 50°C.
In comparison with sodium alkylsulfates (R_iOSO₃Na), the propane sultone derivatives exhibited lower Krafft point and cloud point, excellent surface tension and foaming power even at lower concentrations. The foam stability of these derivatives was similar to each other, but that of fatty acid derivatives was slightly inferior to the others.
The CMC values of the propane sultone derivatives were lower than those of sodium alkylsulfates, and relationship between the CMC and the number (N) of carbon atoms in the alkyl chain (R_i) was expressed as follows.
R_iOC₃H₆SO₃Na ; log CMC =1.15 - 0.292 N
R_iCOOC₃H₆SO₃Na ; log CMC = 0.99 - 0.296 N
R_iOSO₃Na ; log CMC =1.39 - 0.292 N
Furthermore, the relationship between the log CMC and the length of surface active ion (L, Å) could be represented as the following equations.
R_iOC₃H₆SO₃- ; log CMC = 3.09 - 0.233 L
R_iCOOC₃H₆SO₃- ; log CMC = 3.17 - 0.233 L
R_iOSO₃-; log CMC = 2.37 = 0.231 L
From these equations it is suggested that the hydrophilic groups of -O- and -COO- decrease the lipophilic property of the hydrocarbon chain by 1.4 and 0.7 units of -CH₂- respectively in regard to the CMC value.