Diode-array detection has been applied to evaluate the chemical composition of block copolymers from chromatographic data. Two different modes of chromatography have been used for separation: size exclusion chromatography and adsorption chromatography, based on tertiary mixed eluents, comprising tetrahydrofuran, acetonitrile and dichloromethane on a microcolumn, packed with 5 pm wide-pore silica gel (mean pore size 300,~). U.v. spectral data acquired on-line were manipulated to generate spectral suppression chromatograms in order to selectively detect each component of a block copolymer chromatographed under both size exclusion and critical thermodynamic conditions. The content of polystyrene and poly(methyl methacrylate) residues in a series of model block copolymers of nominally constant composition (~ 1:1, w/w), but differing in molecular weight, could be rapidly determined by this novel combination of chromatographic selectivity enhanced by digital discrimination. Thus, diode-array detection has significant potential for fast on-line monitoring of polymer processing
Посилання на статтю:
Diode-array detection with spectral suppression in size exclusion and adsorption chromatography for rapid evaluation of chemical composition in block copolymers of styrene and methyl methacrylate* / Tatiana M. Ziminat, Anthony F. Fell and John B. Castledine // Polymer. – 1992. – Vol 33. – P. 4129-4135.
