ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Sulfite cooking of viscose cellulose. VI. The decomposition of cooking acid at higher temperatures with the co.ovrddot.operation of sugars

I. Slávik

Slovak Academy of Sciences, Bratislava

Abstract: cf. C.A. 52, 7689c. The combined effect of SO₂ and glucose solns. at high temps. at various pH values was studied and evaluated according to the amt. of H₂SO₄ and free S liberated from thiosulfates and polythionates. At a pH above 2.0, glucose is decompd. extensively and oxidized to gluconic acid and there is, in the ratio to H₂SO₄, more of S formed than that corresponding to autoxidation of SO₂. At pH 1.4 little gluconic acid is formed and glucose degraded to a lesser extent to levulinic acid with 5-hydroxymethylfurfural as an intermediate product. Dark condensation products are also formed. In solns. so prepd. that at the end of cooking pH reaches 1.7-1.8, the levulinic acid and furfural compds. are not present and considerably less of gluconic acid is formed. In this case the ratio of H₂SO₄ to S approaches the theoretical one. These results indicate that there is autoxidation occurring and not an oxidation-reduction reaction. Me glyoxal was not found in the solns. cooked without alkali.

Full paper in Portable Document Format: 1212a703.pdf (in Slovak)

Chemical Papers 12 (12) 703–712 (1958)