Composition analysis for butyl acrylate (BA)/methyl methacrylate (MMA)/alpha-methyl styrene terpolymers was carried out by NMR spectroscopy methods. H-1-NMR was used primarily for this analysis, but because the method did not provide independent measurements for the BA and MMA fractions, the terpolymer composition analysis was open to higher than normal levels of uncertainty. Supplementary analyses were made with quantitative C-13-NMR methods to confirm the results from H-1-NMR (quantitative C-13-NMR was used to provide corroboration of selected composition analyses). To confirm spectral assignments in the H-1- and 13C-NMR spectra, heteronuclear multiple quantum coherence and I Modulated Spin Echo (JMOD) pulse sequences were used. (c) 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:2093-2098,2007