Analysis of compositional drift in methyl methacrylate and n-butyl acrylate copolymers synthesized by atom transfer radical polymerization using 13C{1H} NMR spectroscopy

Compositional variations occurring along the chains in the copolymers of methyl methacrylate (M) and n-butyl acrylate (B) were investigated using C-13{H-1} NMR spectroscopy. Copolymerization of methyl methacrylate and n-butyl acrylate with varying infeed ratio was done using Atom Transfer Radical Polymerization. Copolymer compositions were determined from H-1 NMR spectra. Percentage conversion was studied gravimetrically. Analysis of the variations of beta methylene dyads fractions and M- and B-centered triad fractions with conversion was done using Distortionless Enhancement by Polarization Transfer (DEPT) experiments to have a better insight to trend followed by the compositional drift with conversion. The experimental results were found to be in good agreement with the simulated data indicating towards the uniformity along the copolymer chains resulting in the formation of gradient copolymers.