THE MEASUREMENT OF MOLECULAR-WEIGHT DISTRIBUTION OF SOME POLYDISPERSE POLYSTYRENES BY REVERSED PHASE AND SIZE EXCLUSION CHROMATOGRAPHY

The methods of size exclusion chromatography and reversed phase gradient elution high performance liquid chromatography were compared for the analysis of the molecular weight distributions of six general purpose polydisperse polystyrenes. The results indicated that for samples within the exclusion limit of the size exclusion columns the agreement between the number, weight and z-average molecular weights for the size exclusion and reversed phase methods was good. The reversed phase method appears less sensitive to concentration effects than the size exclusion method and offers possibilities of better resolution.