Beitrag zur kenntnis der polymerisationsanregung mit redoxsystemen, die metallverbindungen enthalten

Abstract

SUMMARY:Apart from the redox system peroxide/vanadium accelerator, only the combination hydroperoxide/cobalt (11) salt has obtained industrial importance for the 165 CHRISTIAN SRNAfree -radical initiated polymerization of unsaturated polyester resins at room temperature. Other metal compounds either do not react with peroxides to form radicals or only do so at a very low rate.It has been found that the presence of promotors or additional accelerators not only increases the action of cobalt compounds, but also activates compounds of manganese, copper and iron to such a degree that they can be used for initiating the polymerization of unsaturated polyester resins at room temperature.The following compounds were used as promotors in the investigations : N,N-dimethylaniline, t-dodecyl mercaptan, n-dodecyl mercaptan, sodium benzenesufiate, a-hydroxymethyl phenylsulfone, N-methyl-bis-(phenylsulfonemethyl)amine, ethyl acetoacetate, acetylacetone, and acetoacetdiethylamide.When these promotors are used merely in conjunction with peroxides, there is no formation of radicals or the rate of radical formation is only low. In contrast to this, the combination peroxide/metal compound/promotor has a remarkably high effectiveness as a polymerization initiator.The use of redox systems of this type is not confined to initiate polymerization of unsaturated polyester resins. They are also suitable for polymerizing other systems which can be subjected to free-radical initiated polymerization, e . g. acrylate syrups, styrene syrups and monomers.For each monomer system the optimum combination must be ascertained.