| 摘要 |
In a rapid determination of the degree of ethoxylation of highly ethoxylated nonionic surfactants, a mixture is prepared of 20 to 50% by weight of a highly ethoxylated nonionic surfactant and 80 to 50% by weight of two hydrophobic organic solvents, one of which produces a clear solution of the surfactant and the other produces a turbidity when mixed with the surfactant. The solvent producing a clear solution is used in a ratio by weight of 50:50 to 20:80 to the hydrophobic solvent producing a turbid solution. The temperature is determined at which the initially turbid solution becomes clear or the solution which has become clear as a result of heating becomes turbid. From this temperature the degree of ethoxylation is determined using a calibration curve plotted beforehand. The method can be carried out so rapidly that it can be used during the ethoxylation reaction to determine the end point of the latter.
|
