The technique of alkali fusion reaction gas chromatography has been applied to the determination of alkyl and aryl groups in polysiloxanes. The method involves the quantitative cleavage of ail organic substituents bonded to silicon, producing the corresponding hydrocarbons. Reactions are driven to completion, with no apparent decomposition, in less than 10 minutes by fusing the sample with potassium hydroxide in an Inert atmosphere. After concentration of the volatile products, they are separated and determined by gas chromatography. Sample losses are minimized by performing the total analysis in a single piece of apparatus. Fluids, gum rubbers, and resins are handled with equal ease. The percent relative standard deviation of the method is 1.0%; the average deviation between experimental and theoretical or check method results Is 0.5% absolute.Polysiloxanes, also referred t o as silicones or polyorganosiloxanes, are commercially important because of unique properties resulting from their dual organic-inorganic composition. The analytical chemistry of this class of polymers has been reviewed in a recent monograph by Smith ( I ) .Spectrometric techniques, such as IR and NMR, are powerful tools for the qualitative and quantitative analysis of many functional groups in t h e intact polymer. Alternatively, these organic substituents can be cleaved from the polymer to produce simple compounds that can b e determined by chemical or instrumental techniques.Alkyl and aryl substituents are readily detected by t h e above approaches, b u t quantitative analyses of these groups may be difficult with existing methodology. Instrumental techniques such as N M R (2, 3 ) , IR (4-13), and UV (14-17) spectrometry are useful for analyzing methyl and/or phenyl groups in silicone polymers, but they are generally unable t o differentiate isomers or homologues. Chemical cleavage coupled with a separation technique is a more selective approach. Several reaction-based methods have been reported for t h e quantitative determination of alkyl and aryl groups

The technique of alkali fusion reaction gas chromatography has been applied to the analysis of imide monomers and

No abstract