OP-II-3

PP-I-54KINETICS OF AQUEOUS ALKALI OXIDATION OF NONYLPHENOLETHOXYLATE ON PALLADIUM CATALYSTStaroverov D.V., Varlamova E.V., Suchkov Yu.P.D. Mendeleyev University of Chemical Technology of Russia, Miusskaya Sq. 9,125047 Moscow, Russia; E-mail: stardv@pxty.ruAqueous alkali oxidation of ethoxylates on noble metal catalysts is the selectivemethod of anionic modification of nonionic surfactants:RO(CH 2 CH 2 O) n-1 CH 2 CH 2 OH + O 2 + NaOH → RO(CH 2 CH 2 O) n-1 CH 2 COONa + 2 H 2 O.Reaction products are the ether carboxylates labelled as a perspective class ofsurfactants with expanding application range. Valuable properties of ethercarboxylates are determined by a structure of molecules: polyether chain is thescreen softening the antagonism between a hydrophobic radical and anionic(carboxylate) function. Sometimes ether carboxylates are called cryptoanionicsurfactants to underline their soft anionic nature. Usage of a method of directethoxylates oxidation by oxygen allow to refuse additional reagents for synthesis ofether carboxylates and to avoid formation of accompanying impurities and a waste.The kinetics of ethoxylates oxidation on palladium catalyst has been investigated onexample of Neonol AF9-6 (nonyl phenol ethoxylate with ethoxylation degree 6). Thecatalyst is 2 % Pd on activated carbon.Ethoxylates and ether carboxylates solutions possess the high foaming abilityimposing unmanageable restrictions on hydrodynamics as well as on mass and heattransfer. Therefore in the network of present study we have developed theexperimental technique for carrying out of reaction on rotatory film device with thevolumetric control. Using this technique we have excluded foaming and provided akinetic mode of process.Other feature of ethoxylates and ether carboxylates aqueous solutions isexistence of the isotropy top temperature limit ("cloud point"). Cloud point increaseswith growth of conversion of ethoxylate into ether carboxylate. In the course ofoxidation it leads to change of reaction solution phase state: the unstable dispersionof coacervate (hydrated "organic" phase of a surfactant) turns to an isotropic micellarsolution. Accordingly, we have differentiated "emulsion" and "micellar" phase modes314