Abstract
Cotelomers of acryric acid and n -octyl acrylate, 2-ethylhexyl acrylate or 2-phenylethyl acrylate with same carbon numbers (abbreviation by 2.1NoA-1.2AA, 1.9EhA-2.9AA and 1.6PeA-3.0AA, respectively; 2.1, 1.9 and 1.6 mean number of hydrophobic functions, 1.2, 2.9 and 3.0 mean number of carboxylate functions) were prepared by the radical cotelomerization in presence of 2-aminoethanethiol hydrochloride and examined for surface activity. Critical micelle concentrations (cmcs) of 2.1NoA-1.2AA, and 1.9EhA-2.9AA were 1/16 and 1/5 of that of conventional surfactant of sodium n -octanoate. Surface tensions of aqueous solutions of 2.1NoA-1.2AA, 1.9EhA-2.9AA and 1.6PeA-3.0AA were 32.3, 27.3 and 41.1 mN m-1 at each cmc, respectively. 2.1NoA-1.2AA having straight alkyl chains and 1.9EhA-2.9AA having branched alkyl chains gave figh foaming abilities in water as well as in hard water. 2.1NoA-1.2AA had high foam stability, while 1.9EhA-2.9AA showed poor stability. The highly stable oil-in-water type emulsions, which were brought about by shaking toluene with aqueous solutions of cotelomers, were formed by using 1.6PeA-3.0AA having aromatic nucleus. Interfacial tensions between aqueous solutions of 2.1NoA-1.2AA, 1.9EhA-2.9AA and 1.6PeA-3.0AA and toluene were 4, 8 and 1mN m-1, respectively.
