Some Properties of Multi-chain Type Nonionic Surfactants Derived from Pentaerythritol

Abstract

Several new types of nonionics have been prepared by polyaddition of ethylene oxide(EO) to homologous series of higher alkylethers of pentaerythritol with a general formula, (ROCH2)x•C(CH2OH)4–x (x=1~3, R=n–Cs~n–C16). Cloud point(Cp), aqueous surface tension (γCMC) and CMC of these nonionics were compared with those of conventional nonionics, in order to clarify the effects of the multi–chain structure and the polyether type joint group. (1) Within a series of nonionics with the same HLBd (Davies's HLB value), higher homologues showed higher Cp. (2) When the number of alkyl chain in the hydrophobe consisting of a given number of total carbon (N) increased, Cp and γCMC lowered and CMC increased in general. But the difference in TCMC and CMC was little between dialkyl and trialkyl series. No significant difference in γCMC was observed among trialkyl homologues of R = C3~C6. (3) Plots of log CMC vs. N for monoalkyl nonionics gave a straight line, whereas a concave curve was found for polyalkyl, especially for trialkyl series. (4) No apparent contribution of ether oxygen in the joint group to the hydration was observed. (5) As for the series containing the hydrophile of multi–chain structure, it was found that (1) Cp was considerably lower than that expected from the HLBd, (2) log CMC decreased linearly with increasing mole number of EO(m), (3) the slope of log CMC — m line was more steep along with the higher R and the larger the number of POE chain. These results were discussed from a viewpoint of configuration and hydration of POE chains in nonionics. © 1973, The Chemical Society of Japan. All rights reserved.