An NMR study of poly(furfuryl alcohol) prepared with p-toluenesulphonic acid

Abstract

Poly(furfuryl alcohol) with M n = 2–2.2 × 103 was prepared using p-toluenesulphonic acid in methylene chloride. Polymer structures were determined by 1H and 13C NMR spectroscopy. The 1H NMR spectrum indicated the predominance of linear sequences and the absence of CH2OCH2bonds in the polymer. The 13C NMR spectrum displayed broad signals between 30 and 42 ppm, observed previously only in the CP/MAS NMR spectra of the crosslinked polymer and attributed to branched sequences. The 13C NMR DEPT treatment excluded the possibility that the broadening of the signals was due to the medium and suggested instead that the cause was the number of possible configurations in the polymer chains associated with the dispersion of branches and chain lengths. Quantitative measurements (relaxation interval D1(s) = 20 for the extinction experiments of the nuclear overhauser enhancement) provided both the main polymer structure and the ratio of branching to linear sequences, which ranged from 1:2 to 1:3. © 1999 Society of Chemical Industry