Liquid crystalline polycarbosilanes and poly(di‐n‐butylsiloxane) as stationary phases in gas chromatography

Abstract

AbstractBACKGROUND: Due to their wide variety of applicable substituents and relative ease of synthesis, liquid crystalline polymers are extensively studied as stationary phases in gas–liquid chromatography (GC). Although side‐chain liquid crystalline polycarbosilanes, due to their higher thermal and chemical stability compared to polysiloxanes, seem to be natural candidates for GC stationary phases, they have not yet been tested for such applications.RESULTS: Five stationary phases for GC, based on liquid crystalline polycarbosilanes and polysiloxanes, capable of generating nematic, smectic and condis mesophases were studied. HETP values and Kováts retention indices were calculated, using a series of probes (linear alkenes, benzene, xylene, toluene, cumene, mesitylene), and compared with those obtained for a typical stationary phase based on polydimethylsiloxane (OV‐101). The separation abilities of polycarbosilanes and poly(di‐n‐butylsiloxane) were evaluated using inverse gas chromatography.CONCLUSION: The results suggest that polycarbosilane‐based phases have similar separation properties to those of polysiloxane liquid crystals with some advantages such as higher thermal and chemical stability and good, linear dependence of retention times on temperature. The poly(di‐n‐butylsiloxane)‐based phase did not exhibit any advantages over the typical OV‐101 phase. Copyright © 2009 Society of Chemical Industry