Kinetic study of the phase-transfer catalyzed etherification of 4,4'-bis(chloromethyl)-1,1'-biphenyl with phenol in an alkaline solution of KOH/organic solvent two-phase medium was investigated. The reaction was carried out in a stirred batch reactor under mild operating conditions. During or after completing the reaction, the mono-substituted product (4,4'-(chloromethylphenoxy-methyl)-1,1'-biphenyl) and the di-substituted product (4,4'-bis(phenoxymethyl)-1, 1'-biphenyl) are both produced. Effects on the reaction due to various operating conditions, such as agitation speed, amount of water, amount of organic solvent, amount of phase-transfer catalyst, amount of potassium hydroxide, kind of phase-transfer catalyst, kind of organic solvent, inorganic salt and temperature were studied in detail. A rational mechanism of the etherification was proposed based on the experimental observation and a kinetic model was developed. In examining nine kinds of phase-transfer catalyst, tetraoctylammonium bromide was found to be the best for increasing the reaction rate. The inorganic salts, such as potassium iodide or sodium iodide play an important role in enhancing the reaction rate. Hoffmann elimination is used to explain the peculiar behavior in studying the effect of the KOH on the apparent rate constants. The apparent activation energies for the etherification were E-al = 23.7 kcal/mol and E-a2 = 31.5 kcal/mol, respectively, using tetra-n-butyl-ammonium bromide (TBAB) as the catalyst. (c) 2006 Elsevier B.V. All rights reserved.