ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The Radical and Ion-Radical Mechanism of Polymerization of 2,6-Xylenol. I.  Formation of Polymer Radicals and Consecutive Products

A. Tkáč and J. Kresta

Institute of Chemical Physics, Department of Physical Chemistry, Slovak Technical University, Bratislava 1

Abstract: It was proved that on the surface of the crystalline copper(II) complexes СuСl(ОСНз) • 2 pyridine and CuCI₂ • 2 cyclohexylamině in a silicone paste, polymer phenoxy radicals were generated from 2,6-xylenol of the same type as those formed in a benzene solution in the presence of Ag₂0. The generated primary radicals with different spin density in the para position and on the oxygen atom can recombine in two ways. By recombination in the para position (С —С coupling) bisphenol (a derivative of 4,4-dihydroxydiphenyl) is formed and by recombination through the oxygen atom (С —О coupling) it is a dimer. In the beginning state of the reaction the formation of bisphenol is preferred and the product of its oxidation is diphenoquinone (DPQ). In course of the polymerization by recombination of the dimer radicals, polymer radicals with a sufficiently long life time are produced, so that their level constantly increases and a stationary concentration indicable by the EPR method is reached. In this condition, recombination of the primary radicals with the polymer radicals is statistically more favourable than the С —С coupling and the concentration of DPQ does not increase more.

Full paper in Portable Document Format: 243a189.pdf

Chemical Papers 24 (3) 189–197 (1970)