Dichloroacetic acid chemistry

Figure 18.5 Helix-coil transitions of poly(L-benzyl glutamate) in a mixture of dichloroacetic acid and heptane showing the variation of the apparent molecular weight (M in their notation) and the radius of gyration. Source Reprinted with permission from Cowie JMG. Pure Appl Chem 1970 23 355 [33], Copyright 1970 International Union of Pure and Applied Chemistry (after Marchal E, Strazielle C. Compt Rendu 1968 C267 135. Academie Franjaise de Science).

Since the chemistry of amphoacetates is related to a large extent to that of betaines, the by-products (apart from the amine) are almost identical. Sodium chloride is contained in a range of 6% for monoacetates, and up to 12% for diacetates. Glycolic acid, formed by hydrolysis from chloroacetic acid, is contained at 0.5-1.0% but may be as high as 4% in some grades of the surfactant. Dichloroacetic acid and residual monochloroacetic acid are found in similar concentrations as in betaines. Glycerin is not usually present, because the oil is not normally used as a raw material. However, a complete analysis of the product composition still remains to be carried out. 

The chemistry of dichloroacetic acid is typical for halogenated organic acids. It is a member of the chloroaeetie acids family. The dichloroacetate ion is produced when dissolved in water. As an acid with a pKa of 1.48, pure dichloroacetic acid is very corrosive and extremely destructive to tissues of the mucous membranes and upper respiratory tract. 

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