Poly(acrylonitrile-co-methyl Methacrylate-co-methyl acrylate): Synthesis and Stereosequence Distribution Analysis by 2D NMR AJAIB S. BRAR, ASHOK K. GOYAL, SUNITA HOODA,* RAVI SHANKAR Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India Received 17 September 2008; accepted 24 September 2008 DOI: 10.1002/pola.23096 Published online in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: Terpolymers of acrylonitrile (A), methyl methacrylate (B), and methyl ac- rylate (M) were synthesized under optimized atom transfer radical polymerization conditions using 2-bromopropionitrile as an initiator and CuBr/dinonyl bipyridine as a catalyst. Variation of the feed composition led to terpolymers with different compo- sitions. Composition of synthesized terpolymers were calculated from quantitative 13 C{ 1 H} NMR spectra. Number average molecular weight and polydispersity index were determined by gel permeation chromatography. The overlapping and broad sig- nals of the terpolymers were assigned completely to various compositional and config- urational sequences by correlation of one-dimensional 1 H, 13 C{ 1 H}, and distortionless enhancement by polarization transfer and two-dimensional heteronuclear single quantum coherence (HSQC) and total correlation spectroscopy (TOCSY). 2D HSQC NMR study shows one to one correlation between carbon and proton signals, while 2D TOCSY spectra were used to confirm 1, 2 bond geminal couplings between none- quivalent protons of same methylene group. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 25–37, 2009 Keywords: acrylonitrile; atom transfer radical polymerization (ATRP); copoly- merization; gel permeation chromatography (GPC); methyl acrylate; methyl methacrylate; microstructure; NMR; terpolymer INTRODUCTION Multicomponent polymerization has continued to evoke interest in both academic and industrialists alike. Addition of a third component to a binary copolymer can give desirable chemical, physical, and mechanical properties that differ from those of copolymers. Therefore, terpolymerization pro- vides a convenient method for synthesizing new polymeric materials with wide range of proper- ties. 1–3 Copolymers based on methyl methacry- late, methyl acrylate, and acrylonitrile are mate- rials of significant commercial importance and have wide applications in rubber, plastic, textile, and membrane technologies. 4–7 Utility of these copolymers in a specific industrial application depends on molecular weight (M n ) and structural properties. 8 In the past, synthesis of these copoly- mers has been accomplished through conven- tional free-radical polymerization which lacks the ability to control polymer structure and M n . The advent of atom transfer radical polymerization (ATRP) 9–12 has minimized these drawbacks of free-radical polymerization by showing advan- tages in terms of control over M n , copolymer Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 47, 25–37 (2009) V V C 2008 Wiley Periodicals, Inc. *Present address: Department of Chemistry, Acharya Narendra Dev College, Govind Puri, Kalkaji, New Delhi 110019, India Correspondence to: A. S. Brar (E-mail: asbrar@chemistry. iitd.ernet.in) 25