DETERGENCY OF THE 12 TO 18 CARBON SATURATED FATTY ACIDS

摘要

Systems of one surfactant (two anionic and three nonionic types were studied) with an homologous family of soils (the 12, 14, 16 and 18 carbon saturated fatty acids) were explored to determine the relationship of the detergencies of such systems to the physico-chemical nature (HLB, hydrophile-1ipophile balance) of the soils. A series of systems of ethylene oxide homologs of nonyl phenol with the same soils was also investigated.nNeither surfactant HLB nor adsorptive energy of the surfactant polar group, alone, is responsible for the detergency of the 12 to 18 carbon fatty acids.nTwo semi-logarithmic relationships were derived for the nonyl phenol polyethenoxyether-fatty acid systems; namely, linearity of the R (ethylene oxide mole ratio)-log M/CMC and surfactant HLB-log M/CMC functions (M = surfactant concentration giving ca 100% removal of 16 and 18 carbon fatty acids, and CMC = critical micelle concentration).nFatty acid soaps are poor detergents of the fatty acid soils. It is suggested that in such systems the chief action is van der Waa1s adsorption between hydrocarbon chains of the surfactant and soi1, with adsorption increasing with increasing chain length of the former and concentration of the latter. Anionic sodium dodecyl benzene sulphonate is a good detergent of the fatty acids, soil removal being independent of soil chain length.nPolyoxyethylene (23) sorbitan monolaurate and the 12 and 15 ethylene oxide mole ratio adducts of tridecyl alcohol are poor detergents of the saturated fatty acids.