On-line coupling of gradient-HPLC and H-1 NMR for the analysis of random poly[(styrene)-co-(ethyl acrylate)]s

Full Paper: Random poly[(styrene)-co-(ethyl acrylate)]s can effectively ana lysed with respect to the chemical composition distribution by on-line coup led HPLC/H-1 NMR. The separation of the copolymers is conducted on a revers ed-phase column using acetonitrile/tetrahydroturan as the eluent mixture. V ia on-line coupling, the chromatographic peaks are directly transferred int o the NMR spectrometer and analysed on-flow. Information on the chemical co mposition and the chemical heterogeneity of copolymers with high conversion is obtained. The experiments have been carried out using conventional HPLC -grade solvents and no deuterium lock. The results of the on-line HPLC/H-1 NMR investigation have been correlated with a HPLC procedure based on calib ration with narrow-distributed copolymer standards.