Abstract:

Eight halogen quaternary ammonium cationic surfactants containing adamantane structure were successfully synthesized through quaterisation of the intermediate compound-N,N-dimethyl tertiary amine using halogen quaternary ammonium reagents. N-(1-adamantyl)-N,N-dimethylamine was synthesized through the Eschweiler-Clarke methylation reaction in which 1-adamantine and formaldehyde with excess formic acid were used as raw materials. The yields of the eight products were 90%, 85%, 75%，61%，44%，54%，87%, 45% respectively. The structures of all these compounds were confirmed by elemental analysis, IR, and ¹H NMR. Surface tensions of these eight compounds’aqueous solutions with concentration of 0.1% and 1% were measured. The results showed that the surface tensions of these aqueous solutions decreased to different degrees compared with pure water. It was also found that the difference of surface activity among similar structure compounds with different anions (halide ions)was not significant. However, surface activity increased when the carbon chain lengths of the quaternary ammonium reagents increased.