PARTITIONING OF POLYSTYRENE AND POLYOXYPH ENYLENE BY LIQUID-CHROMATOGRAPHY UNDER CRITICAL CONDITIONS

The mixtures of polystyrene (M approximate to 3.3 x 10(4)) and polyoxy phenylene (M approximate to 3.0 x 10(4)) homopolymers were partitioned and analyzed by liquid chromatography under critical conditions. The critical partitioning regime for a Lichrosphere Si-300 column was dete rmined by variation of the composition of a binary solvent (CCl4-chlor oform) and the temperature. A chromatographic system was selected that featured the critical conditions for polyoxyphenylene and in which th e chromatography of styrene was performed in the exclusion regime. It is demonstrated that the chromatography under critical conditions allo ws homopolymers with close molecular masses to be partitioned in the i socratic mode.