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

Poly(furfuryl alcohol) with (M) over bar(n) = 2-2.2 x 10(3) was prepared us ing p-toluenesulphonic acid in methylene chloride. Polymer structures were determined by H-1 and C-13 NMR spectroscopy. The H-1 NMR spectrum indicated the predominance of linear sequences and the absence of -CH2-O-CH2- bonds in the polymer. The C-13 NMR spectrum displayed broad signals between 30 an d 42 ppm, observed previously only in the CP/MAS NMR spectra of the crossli nked polymer and attributed to branched sequences. The C-13 NMR DEFT treatm ent 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 bran ches 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 li near sequences, which ranged from 1:2 to 1:3. (C) 1999 Society of Chemical Industry.