Zusammenfassung
The growing importance of siloxanes in various industrial areas, e.g., health care, cosmetics, automotive and construction industries requires further method development of analysis techniques. In addition, and complementing gas chromatography analysis, a polymer liquid chromatography method for separation of linear and cyclic (poly)dimethylsiloxanes was developed and optimized. By an appropriate ...
Zusammenfassung
The growing importance of siloxanes in various industrial areas, e.g., health care, cosmetics, automotive and construction industries requires further method development of analysis techniques. In addition, and complementing gas chromatography analysis, a polymer liquid chromatography method for separation of linear and cyclic (poly)dimethylsiloxanes was developed and optimized. By an appropriate choice of mobile and stationary phase combinations, separations of up to 30 monomeric units were achieved. Therefore, various HPLC columns were investigated concerning physical and chemical properties, e.g., pore size, silica base material, and column functionality. Furthermore, solubility properties of siloxanes in adsorption- and desorption-promoting solvents were investigated and taking these results into account, the separation was optimized applying a mixture of methanol:water (75:25, v/v) and acetone. The findings indicate that precipitation/re-dissolution effects superimposed by adsorption chromatography play an important role for the efficient separationof a high number of monomer units. Besides method development on an analytical scale, linear poly(dimethylsiloxane) oligomers were separated with preparative polymer HPLC. These fractions of single oligomers allow further investigations of different material properties beyond polymer HPLC. [GRAPHICS] .
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