FUNCTIONALITY TYPE ANALYSIS OF CARBOXY-TERMINATED OLIGOSTYRENES BY GRADIENT HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Carboxy-terminated oligostyrenes, prepared by radical polymerization u sing a dicarboxy- functional initiator, can efficiently be separated b y gradient high performance liquid chromatography (HPLC). On a normal phase chromatographic system, comprising a silica gel stationary phase and a tetrahydrofuran-hexane eluent, elution occurs in the order of i ncreasing polarity of the oligomers and separation into non-, mono-, a nd dicarboxy oligomer fractions is obtained. The chemical structure of the different functionality fractions is determined by matrix assiste d laser desorption/ionization mass spectrometry (MALDI-MS). The result s indicate that further functionality fractions in addition to the car boxy oligomers are formed, due to contamination of the initiator or si de reactions during the polymerization process.