Chromatographic characterisation of copolymers
Copolymers containing hydrophilic and hydrophobic segments find applications as polymeric surfactants in detergent formulations. The properties of such surfactants depend on molecular weight and composition of copolymer chains, and in particular on the heterogeneities in molecular weight distribution and chemical composition distribution within samples. Heterogeneity in copolymer composition may include the presence of a homopolymer which would not be active in a detergent application. In this thesis work is directed to the development of separation methods by reversed phase chromatography to characterise copolymers according to composition. Copolymer systems include acrylic acid/lauryl methacrylate, poly(ethylene oxide)lvinyl acetate, and polyesters based on terephthalic acid, poly( ethylene oxide) and glycerol. The outcome of these separations has been the isolation of poly acrylate and copolymer; poly(ethylene oxide), poly(vinyl acetate) and copolymer from their respective copolymer systems; and the separation of poly( ethylene oxide) and glycerol from the polyester samples. Spectroscopic analysis of the fractions for each copolymer enabled complete characterisation and quantification of the copolymers present.