Abstract
Nonylphenol-formaldehyde condensates whose molecular weights ranged from 527 to 793 were prepared by the condensation of p-nonylphenol with formaldehyde and were allowed to react with ethylene oxide to yield oligomeric surface active agents. Then f ormyl, nitro or amino group was introduced into these products according to the procedure reported in the previous paper. The surface tensions of aqueous solutions of each derivatives were determined and it was found that the surface tensions lowered to about 3235 dyn/cm. Their antimicrobial activities against gram-positive and gramnegative bacilli and fungi were evaluated in terms of minimum inhibitory concentration by a dilution method. Formyl derivatives had the inhibitory activity against gram-negative bacilli and fungi, on the other hand dinitro and diamino derivatives against gram-positive bacilli and fungi. But these oligomeric surface active agents were less active than the monomeric ones, which had the corresponding oxyethylene chain length and the same functional group. No difference in antimicrobial activity was observed in these oligomeric surface active agents which had different molecular weight.
