PREPARATION OF STYRENE DERIVATIVES CONTAINING SULFIDE GROUP - KINETIC-STUDIES ON THE ADDITION-REACTION OF THIOPHENOL TO 1,4-DIVINYLBENZENE

The addition reaction of thiophenol to 1,4-divinylbenzene affords mono-adduct, 4-vinyl-1-[(2-phenylthio)ethyl]benzene with about 70%, and di-adduct, 1,4-bis[(2-phenylthio)-ethyl]benzene. Reaction rate dependence on the reagent concentration was studied by gas chromatography. The reaction rate depends on the first order of the thiophenol concentration and one half order of AIBN concentration. The addition reaction proceeds by a radical chain mechanism and the rate determining step is thought to be the hydrogen abstraction from thiophenol by the intermediate carbon radical. The ratio of the overall reaction rate constants of the first addition (k1) and second addition (k2) to the two vinyl groups of 1,4-divinylbenzene, k2/k1 was estimated using a computer curve fitting method in comparison with the experimental data. The values of k 2/k 1 are in the range of 0.18 to 0.25 at 60°C and 75°C, respectively. The reaction rate constant of the second addition is one fourth to one sixth that of the first addition. High reaction temperature is a disadvantage to obtain much higher yields of the mono-adduct. © 1990, The Society of Polymer Science, Japan. All rights reserved.