2003 Volume 52 Issue 12 Pages 655-662
The pseudo-binary T-X phase diagrams for aqueous mixtures of polyethylene glycol alkyl ethers with chain length distribution were constructed by means of differential scanning calorimetry and were compared with the binary phase diagrams for the aqueous mixtures of surfactants with a homogeneous chain length distribution. The surfactants with chain length distribution were prepared by mixing CnEm (n = 10, 14, and m = 5 - 8) in appropriate molar ratio to provide average chain lengths of n = 12 and m = 6 or 7. The regions of mesophases appearing in the aqueous mixtures of mixed surfactants were essentially the same as those in aqueous mixtures of pure surfactants with chain lengths corresponding to the average chain lengths of the mixed surfactants. This suggests that the aqueous phase behavior of the POE-type surfactants with chain length distribution is determined by the average chain length in both the POE chain and the hydrocarbon chain so long as the chain length difference among the components is not so large.
