Study On The Synthesis And Properties Of Isomeric Fatty Alcohol Polyoxyethylene Ether And Their Derivatives

This paper aim at investigating the surface chemical properties and application of isomeric fatty alcohol polyoxyethylene ether, and derivativing some of them into fatty alcohol sulfates, alcohol ether sulphates and fatty alcohol phosphates which their properties are also studied . The critical micelle concentration (cmc) and the surface tension at cmc (γ_cmc) of isomeric fatty alcohol polyoxyethylene ether are measured with drop volume method at 25℃, and then the maximum surface excess concentration (Γ_max) and the minimum area per surfactant molecule (A_min) can be calculated. At the same time, we also measure their application performances, which show the wet ability is the best, but foam isn't so stability.Different carbon chain lengths(the carbon numbers mainly are 10 and 13)of fatty alcohol sulphate are synthesized by the reaction of isomeric fatty alcohol and chlorosulfonic acid with the molar ratio 1:1.05, reactes for 1h at 30℃,. The products are characterized by IR and their active matter contents are 33.48% and 21.80% which are determined by two-phase titrimetric method.The surface chemical properties of the products are then measured and, compared to the straight one, the results show the properties of isomeric one are less better than the straight chain one.Different carbon chain lengths(the carbon numbers mainly are 10 and 13)of alcohol ether sulphate are synthesized with the same method as above which use the isomeric fatty alcohol polyoxyethylene ether as the raw materials. The products are characterized by IR and their active matter contents are 26.60% and 31.37%. The results of their properties'measurement show that the ability to reduce the surface tension of isomeric alcohol ether sulfosalt is slightly stronger than that of the straight chain ones, and the detergency and wet ability of isomeric alcohol ether sulfosalt are better than the straight ones, but the foaming and emulsification are worse. The micro-polar in the micelle core of isomeric alcohol ether sulfosalt is larger which means the micelle structure is looser, and the critical micellar aggregation number is smaller than the ordinary surfactants.Isomeric alcohol polyoxyethylene ether phosphate is synthesized by the reaction of isomeric fatty alcohol polyoxyethy ether and phosphorus pentoxide. The condition of the reaction is as follow: the reactants'molar ratio is 1.6:1, reactes for 3.5h at 70℃, and then hydrolyses for 1.5h at 60℃, water quantity is 2%. The content of the mono-ester and diester are determined by potentiometric titration. Compared to the ordinary surfactants, the cmc value obtained by the drop volume method is about one order of magnitude lower, which indicates that they have good surface chemical properties. The wet ability and emulsifying property of the isomeric alcohol polyoxyethylene ether phosphate are better than the straight chain ones, but the foaming properties and solubilization power are slightly less. The change rules of the micro-polar in the micelle core are similar to that of the alcohol ether sulphate.