Investigation of Hydroxy-Terminated Low Molecular Weight Polyisoprenes by Liquid Chromatography Methods

Abstract

Model samples of low-molecular weight polyisoprenes and polyisoprenes containing one or two hydroxy endgroups were investigated by using various methods of liquid chromatography. Gel permeation chromatography (GPC) was employed in the determination of molecular weights and their distribution. The validity of the principle of universal calibration was confirmed. Under the given GPC experimental conditions separation was unaffected by the adsorption of hydroxylated polyisoprenes on the column packing used. The bonded -phase liquid chromatography method on columns with the amine phase allowed efficient separation to be achieved according to the content of functional groups. Since there also was separation according to molecular weights, the method allowed an estimate to be made of the molecular weights of fractions with various contents of hydroxy groups. The results obtained proved the possibility of a complex analysis of low-molecular weight polymers with functional groups, such as e.g. liquid rubbers; at the same time, the results of bonded-phase column separation indicate the possible use of this modern liquid chromatography method in the analysis of polymers.