Characterization of Polymer Compositions by Gradient Elution HPLC

Abstract

Synthetic polymers have a molecular weight distribution and, in addition, copolymers composed of multiple monomers have a compositional distribution. Differences in molecular weight and compositional distributions among materials affect the performance of the materials, so it is important to characterize these molecular structures in detail. Gradient polymer elution chromatography (GPEC), one of the solvent gradient HPLC methods, is an effective way to evaluate compositional distribution. In addition, two-dimensional liquid chromatography (2D-HPLC), which combines GPEC with size exclusion chromatography, is a very good analytical method because it allows simultaneous evaluation of composition and molecular weight. In this study, the author examined compositional separation of an acrylic polymer blend and molecular weight analysis of each polymer that makes up the blend. And, the author analyzed the compositional distribution of ethylene vinyl acetate copolymer (EVA), styrene-methyl methacrylate copolymer, and styrene-butadiene rubber (SBR). As these results, it was confirmed that the molecular weights of the polymers constituting the blend samples could be determined separately. It was also found that the compositional distribution of the copolymers could be analyzed in detail, confirming the effectiveness of two-dimensional liquid chromatography.