Analysis of sequence distribution in methyl methacrylate-methyl acrylate copolymers by 13C NMR spectroscopy

Methyl methacrylate (MMA)-methyl acrylate (MA) copolymers, prepared in bulk at 50 degreesC using AIBN as initiator, were characterized by 150 MHz C-13 NMR spectroscopy, including use of the Distortionless Enhancement by Polarization Transfer (DEPT) experiment to obtain methylene and methine carbon resonances as subspectra. Dyad, triad, tetrad and partial pentad distributions were measured from the alpha-methyl, methine and methylene carbon resonances. These were in good agreement with distributions calculated for the copolymers based on monomer feed compositions, conversions and reactivity ratios of 2.60 and 0.27 for methyl methacrylate and methyl acrylate, respectively. (C) 2002 Elsevier Science Ltd. All rights reserved.