Normally liquid final Mannich condensates prepared by reacting a para C.sub.1 -C.sub.15 alkyl phenol with formaldehyde and a first polyoxyalkylene diamine to form an intermediate Mannich condensate that is reacted with formaldehyde and a second polyoxyalkylene diamine to form a final Mannich condensate, the first and second polyoxyalkylene diamines having the formula: ##STR1## wherein R represents hydrogen or methyl and R' represents an alkyl group containing 1 to 4 carbon atoms or cyanoethyl group, and n represents positive numbers having a value of 1 to about 6, the final Mannich condensate having the formula: ##STR2## wherein X and Y are polyoxyalkylene amine groups derived from the first and second polyoxyalkylene diamines and formaldehyde.