Abstract:Lignin structures in wheat straw materials, its chemi-mechanical pulps, the pulps bleached with alkaline H2O2 and the pulps treated by H2O2/NaBH4 were determined in this paper. The results showed that conjugated carbonyl content in the lignin of H2O2 bleached chemi-mechanical pulp decreases by 26.4%, conjugated carbonyl in the lignin of the pulp treated by NaBH4 further decreases by 70.0%. The chromophore in the lignin is broken by bleaching, which improves the pulp brightness. |