Abstract: Strengthened-oxygen total-chlorine-free(TCF) bleaching of NaOH-AQ pulp of low Kappa number from the triploid of Chinese white poplar(Populus tomentosa Carr.) with brightness 37%(ISO), Kappa number 13.5,viscosity 851 mL/g was bleached with a TCF process _QO_P,QP sequence in the laboratory. The bleached pulp with brightness 82.0%(ISO), viscosity 716 mL/g at bleached pulp yield 91.78% was obtained after _QO_P,QP bleaching. The data presented in the paper are useful for developing TCF bleaching sequence for the triploid of Chinese white poplar NaOH-AQ pulp of low Kappa number.

Key words: NaOH-AQ pulp of low Kappa number, triploid of Populus tomentosa Carr., strengthened-oxygen delignification, total-chlorine-free bleaching