Radical copolymers of 2-vinyl pyridine with methyl acrylate and methacrylate. A study of microstructures by 1H n.m.r.

Radical copolymerization of 2-vinyl pyridine with methyl acrylate and methacrylate, respectively, has been carried out in benzene solution with low conversion. The reactivity ratios for the two systems, have been determined using the Fineman-Ross and Kelen-Tüdös methods. The values obtained satisfy the terminal model of copolymerization. The signals sensitive to sequence distribution and configuration in the ¹H n.m.r. spectra are αCH₃ and OCH₃ from methyl methacrylate, OCH₃ from methyl acrylate and the aromatic proton signal from 2-vinyl pyridine. The configurational model for the two types of copolymers is discussed using the information from the signals together with influence of the neighbouring and next-neighbour units on signal splitting.