Determination of Chemical Composition Distribution and Molecular Weight Distribution of Poly(2-(perfluoroalkyl)ethyl acrylate-co-alkyl acrylate) by High Performance Liquid Chromatography and Size Exclusion Chromatography

Abstract

The molecular weight distribution (MWD) of poly(2-(perfluoroalkyl)ethyl acrylate-co-alkyl acrylate) can be determined by size exclusion chromatography (SEC) using an appropriate mobile phase such as a mixture of HCFC225 and THF; however, the chemical composition distribution (CCD) of the copolymer has not been elucidated. We developed an HPLC method for determining the CCD by using a silica-based column modified by polyfluorinated groups, a devised mobile phase gradient system, and an evaporative light scattering detector. In this system, polymers having perfluoroalkyl units are retained on the column through interaction between fluorinated groups and elute at longer retention times. It has become apparent that the copolymer has a broad and characteristic CCD of three components, consisting of fluorinated and non-fluorinated forms and their copolymer. Two-dimensional development of MWD and CCD of the copolymer, called cross-fractionation, is also examined and discussed.