SEPARATION OF HOMOPOLYMER AND COPOLYMER O F OLIGOESTERS IN THE ISOCRATIC MODE AND ANALYSIS OF THEIR FUNCTIONALITY-TYPE DISTRIBUTION BY LIQUID-CHROMATOGRAPHY UNDER CRITICAL CONDITIONS

Hydroxyl-containing oligoesters based on adipic acid and two diols (et hylene- and butylene glycols) were separated with respect to the numbe r of end functional groups using liquid chromatography under critical conditions. For one of the homopolymers, poly(butyleneglycol adipinate ), the critical conditions, which correspond to the point of the coil- adsorbed coil transition, were attained using Zorbax-NH2 standard chro matographic columns and a hexane-methyl ethyl ketone binary solvent. T he quantitative data on the relative content of non-, mono-, and bifun ctional molecules in various commercial copolymers were obtained. Conc urrently, homo- and copolymers (bifunctional with respect to OH groups ) were separated under isocratic conditions.