No abstract

Poly(furfuryl alcohol) with M n = 2±2.2 Â 10 3 was prepared using p-toluenesulphonic acid in methylene chloride. Polymer structures were determined by 1 H and 13 C NMR spectroscopy. The 1 H NMR spectrum indicated the predominance of linear sequences and the absence of ÐCH 2 ÐOÐCH 2 Ð bonds in the polymer. The 13 C 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 13 C 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 con®gurations 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.

Poly(furfuryl alcohol) with different amounts of oxymethylenic bridges was synthesized using trifluoroacetic and p-toluenesulfonic acid. All polymers displayed a tendency to retain acids. The isolated products containing traces of acid became insoluble in a few hours; while neutral material maintains their solubility for at least one month. Polymers stored in solution were stable according to their ¹H NMR spectra. Polymers cross-linked after being exposed to UV radiation. The product of the reaction of polymer with maleic anhydride is useful for preparing negative photoresists

No abstract