Singly γ-carboxypropylated compounds [sample number (7) and (8)] were prepared by the partial OH-carboxypropylation reaction of 6, 6'-dihydroxy 3, 3'-dimethyl-diphenylmethane (2) and 2, 6-bis (2-hydroxy-5-methylbenzyl) -p-cresol (3) with γ-butyrolactone. Beside the above two samples; (4), (5) and (6), which were completely γ-carboxypropylated products derived from p-cresol (1), (2) and (3) as reported in the previous paper, were used as the comparative sample in order to test the surface active properties. The properties of (7) and (8) were measured and compared with other samples (4) (6). Results obtained were as follows.
1) Among the samples studied, only (8) exhibited a considerable decrease in the surface tension and a promotion in the solubilization of Orange OT and in the emulsification of liquid paraffin in water.
2) Studies on the surface tension, solubilization of dye and electrolytic conductivity as a function of concentration of the samples, indicated that the samples (7) and (8) form a micelle, but other compounds (4) (6) do not form micelle.