Abstract: An alkaline peroxide bleaching process was employed for bleaching poplar wood powder(PWP)and effects on bleached PWP brightness of each parameters of bleaching condition s were investigated. The optimal bleaching conditions could be proposed as 27.5% H₂O₂ dosage of 40%(w/w), 90% Na₂SiO₃·9H₂O dosage of 8%, the bleaching pH value of 10-11, the bleaching could be carried out at temperature of 60-70 ℃ for 40 min. The maximum brightness can reach 85%-90% (ISO) of poplar powder, higher than that reported in the literature H₂O₂ bleaching whiteness.

Key words: peroxide hydrogen, bleaching process, poplar wood powder, brightness