Conventional and atom transfer radical copolymerization of n-octyl acrylate–styrene: chemoselectivity and monomer sequence distribution by 1H NMR

Octyl acrylate and styrene (OA–St) were copolymerized by conventional polymerization at 80 °C and atom transfer radical polymerizations at 130 °C in different feed ratios (0.1–0.9 mole fraction of OA) using benzoyl peroxide and cuprous chloride/2,2′-bipyridine/1-phenyl ethyl chloride respectively. Two linear (Fineman–Ross, Kelen–Tüdös) methods and a nonlinear least-squares method were employed for determination of monomer reactivity ratios (rOA=0.30±0.02 and rSt=0.69±0.04). Integrated intensities of the three peaks observed in the 1H NMR spectra of –OCH2 group (3.2–4.2 ppm) were used to determine the mole fraction of 111, 112 or 211 and 212 triad sequences in the copolymers. In addition, the rOA value was used for theoretical determination of mole fraction of these triad sequences. Well-agreed theoretical and experimental values helped us in determining most probable mole fractions of the triad sequences of monomers.