New silarylene/methylphenylsiloxane copolymer stationary phase for open tubular gas chromatography

A new silanol‐terminated silarylene/siloxane copolymer, having 30% phenyl and 1.5% vinyl substitution, has been evaluated for use as a stationary phase in gas chromatography. The polymer was found to be auto‐cross‐linkable. The highest degree of immobilization (90%) was obtained at relatively low temperatures (300°C). The auto‐cross‐linking at lower temperatures might be due to a silanol catalyzed reaction of vinyl groups. At higher temperatures (350–370°C) scission of phenyl groups and the formation of branched structures are the dominating immobilization reactions. Column polarity is thereby decreased. Thermal stability was excellent at 370°C after conditioning at this temperature. The utility of the columns was illustrated by the separation of polycyclic aromatic compounds.