Hexenuronic acid reactions in chlorine dioxide bleaching -aspects on in situ formation of molecular chlorine

摘要

The reactivity of chlorine dioxide towards hexenu- ronic acid (HexA) formed during kraft cooking has been investi- gated. It is claimed that chlorine dioxide itself has a certain reac- tivity, although especially in the D_0 position f the bleaching this reactivity is kinetically hindered and the degradation of HexA in such a position therefore limited. The in situ formation of ele- mental chlorine turns out to be crucial for the efficiency of the chlorine dioxide bleaching in many aspects.