Synthesis and characterization of sulphonated PEES copolymers by NMR spectroscopy

• Published in: European polymer journal Vol. 42; no. 6; pp. 1423 - 1432
• Main Authors: Muthu Lakshmi, R.T.S., Vyas, M.K., Brar, A.S., Varma, I.K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2006; Elsevier
• Subjects: 2D NMR; Applied sciences; Exact sciences and technology; Microstructure; Organic polymers; Physicochemistry of polymers; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; SPEES copolymers; Microstructure; 2D NMR; SPEES copolymers; Solution polycondensation; Molecular structure; Polymer solid electrolyte; Organic siloxane; Ether copolymer; NMR spectrometry; Experimental study; Functional polymer; Sulfone copolymer; Heteronuclear correlation; Two dimension spectrometry; Sulfonate copolymer; Preparation; Copolycondensation; Aromatic copolymer; Proton; Carbon 13
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2006.01.002

Two sulphonated PEES copolymers were synthesized by reacting 75 or 60 mol% silylated hydroquinone sulphonic acid and 25 or 40 mol% of hydroquinone with 4,4′-difluorodiphenyl sulphone. The number average molecular weights determined by GPC were 13.250 and 12.050 g/mol. In the FTIR spectra, in addition to the characteristic absorption bands due to aromatic skeleton, absorption bands associated with sulphonic acid groups were observed at ∼3500, 1172, 1080, 1026, and 706 cm −1. In 1H NMR, the aromatic proton resonance signals were observed between δ = 6.99 and 7.96 ppm. 13C{ 1H} NMR spectra of these copolymers were complex and in order to resolve this, two-dimensional (2D) NMR techniques were utilized. Heteronuclear single quantum coherence (HSQC), total correlated spectroscopy (TOCSY), and heteronuclear multiple bond correlation (HMBC) were used for assigning the structure of the copolymers.