MECHANISM OF INITIATION OF THE CURING OF ANAEROBIC ADHESIVES

摘要

A review is presented of the literature on studies of the mechanism of initiation of the curing of anaerobic composites, which are based on polyfunctional acrylic monomers and balanced initiating and stabilising systems, by a system consisting of cumyl hydroperoxide, dimethyl-p-toluidine and o-sulphobenzoic acid imide. The observed rapid curing of adhesives in the narrow gap between copper and steel surfaces is due to conversion of the metal to the lowest degree of oxidation, catalytic decomposition of the hydroperoxide, consumption of the oxygen in the composite, and subsequent uninhibited radical polymerisation of the acrylates. These events are shown to be possible because of the emergence in the anaerobic composite of charge-transfer complexes between the electron donor and acceptors which, with the participation of oxygen, are capable of generating ion-radical pairs. Reactions of the transformation of the accelerator cation radical and the oxygen anion radical cause the curing of the anaerobic composite on any metal surface. 45 refs. (Article translated from Plast.Massy, No.6, 2007, p.26-31)