Polysiloxane stationary phases containing tolyl and cyanopropyl groups: oxidation during cross-linking

Abstract

The majority of studies on non-extractable stationary phases have been done using the methylsilicones. However, there is a need for non-extractable phases containing different functional groups, such as phenyl and cyanopropyl. Tolyl groups have been incorporated into these stationary phases to facilitate free-radical cross-linking. However, it was found that tolyl and cyanopropyl groups can be oxidized during curing with peroxides, producing stationary phase films that are active and thermally unstable. If, on the other hand, azo compounds are used as the free radical generators, these problems are avoided.