Radical copolymerization of N-vinylcarbazole and p-bromostyrene: determination of monomer reactivity ratios by SEC-multidetection

N-Vinylcarbazole (A)/p-bromostyrene (B) copolymers were prepared by radical copolymerization. Size exclusion chromatography (SEC) equipped with a refractometer and UV–vis spectrophotometer was found to be a very convenient technique to follow copolymerizations and to determine monomer conversions, copolymer composition, average molecular weights, polydispersity indexes versus time. The monomer reactivity ratios rA (N-vinylcarbazole) and rB (p-bromostyrene) were determined by using the Finemann–Ross (FR), the inverted Finemann–Ross (IFR), the Kelen–Tüdos (KT), and the fitting curve graphical methods. The four methods were in good agreement and led to very different values for rA (0.55) and rB (12.3) which induces a preference for the incorporation of B in the copolymer structure. Eventually, with these results the influence of initial feed on the microstructure of the copolymer has been predicted.