Synthesis and surface activities of multi-ammonium cationics derived from n-octadecyl glycidyl

摘要

In this study, cationic surfactants having two, three or four hydroxyl groups were synthesized by the condensation reaction of n-octadecyl glycidyl ether and amine (methyl amine and dimethyl amine) followed by the quaternization with dimethyl sulfate. The structure of a resulting product was determined by 1H NMR and FT-IR spectroscopies. Interfacial tensions measured as a function of time for n-decane drops brought into contact with 1 wt. % surfactant solutions at 25 C indicated that the interfacial tension decreased over a period of about 10-15 min to an equilibrium value. The results of contact angle measurements indicate that C18-BADM surfactant having four hydroxyl groups is the best wetting agent among others studied. Moreover, the excellent adsorption capacity of C18-BADM system suggests that it can be used as a softening agent during a laundry process. The results of foam stability measurement were consistent with those of CMC and contact angle. The percentage of foam volume decrease was found to increase with the hydrophilicity of a surfactant.