In this article, the kinetics and mechanism of the free-radical polymerization of acrylonitrile (AN) using potassium peroxydisulfate (PDS) as a water-soluble initiator in the presence of synthesized 1,4-bis(triethyl methyl ammonium) benzene dichloride (DC-X) as a phase-transfer catalyst (PTC) were studied. The polymerization reactions were carried out under inert and unstirred conditions at a constant temperature of 60 +/- 1 degrees C in cyclohexane /water biphasic media. The rate of polymerization (R-p) increased with an increase in the concentrations of AN, PTC, and PDS. The order with respect to the monomer, initiator, and PTC was found to be 1.0, 0.5, and 0.5, respectively. R-p was independent of the ionic strength and pH of the medium. However, an increase in the polarity of the solvent slightly increased the R-P value. On the basis of the obtained results, a mechanism is proposed for the polymerization reaction. (c) 2007 Wiley Periodicals, Inc.