Analysis of Compositional Drift in Methyl Methacrylate and n-Butyl Acrylate Copolymers Synthesized by Atom Transfer Radical Polymerization Using 13C{1H} NMR Spectroscopy

Abstract

Compositional variations occurring along the chains in the copolymers of methyl methacrylate (M) and n-butyl acrylate (B) were investigated using 13 C{ 1 H} NMR spectroscopy. Copolymerization of methyl methacry- late and n-butyl acrylate with varying infeed ratio was done using Atom Transfer Radical Polymerization. Copolymer compositions were determined from 1 H NMR spectra. Percentage conversion was studied gravimetrically. Analysis of the variations ofmethylene 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. (DOI 10.1295/polymj.37.316) Synthesis of well-defined polymers has always been an area of interest in polymer chemistry. The architec- ture and composition of the copolymers play a vital role as they greatly influence the physical properties. Hence, the knowledge about the composition and dis- tribution of monomer units along the macromolecular chain is very important to correlate structure-property relationship. 1,2