Effects of Mg-based alkaline peroxide bleaching on the characteristics of poplar bleached chemi-thermomechanical pulps

摘要

Mg-based alkalis partially substituting for NaOH and performing as an alkali source in the peroxide bleaching of high-yield pulps,provide an effective way to lower the negative effects caused by NaOH.This work explored the effects of Mg-based alkali on the characteristics of poplar bleached chemi-thermomechanical pulps(chemical components,charge characteristics,fiber morphology,surface lignin content and relative bonding area),and further investigated their effects on the strength properties.The results showed that the tensile,tear and burst indices of the pulp were decreased as the substitution percentage of MgO for NaOH increased,and the changes of the above characteristics caused the reduction of strength properties.