Reactivity ratio and sequence determination of ethyl methacrylate-butyl methacrylate copolymers by NMR spectroscopy

493-496Ethyl methacrylate-butyl methacrylate copolymers have been prepared in bulk at 70° using benzoyl peroxide as the initiator. Compositions ofthe copolymers have been found by 1H-NMR spectroscopy using the ratio of the intensity of downfield protons to that of total protons. Reactivity ratios have been calculated by the method of Kelen-Tudos [J macromol Sci Chem, A9(1) (1975) 1] and Fineman-Ross [J polym Sci, 5(1950) 259]. 13C {1H}-NMR spectra of the copolymers have been recorded and analyzed. Multiplicity of carbon signals is attributed to tacticity within the copolymer. Triad sequence distributions are determined from reactivity ratios using the terminal model Harwood's computer program, as the copolymers are statistical in nature