Abstract:

In order to find out the difference between juvenile and mature wood of Populus simonii×P.nigra, this paper compared their chemical composition, fiber morphology and the pulping property. The results showed that the contents of phenethyl alcohol extractives, cellulose and lignin in the juvenile wood were higher than those in the mature wood, the holocellulose contents in the juvenile wood were lower than those in the mature wood.The fiber length in the juvenile wood was lower than that in the mature wood. Adopting orthogonal experiment on kraft pulping, we analysed that it was very significant for the heat preservation time and the dosage of alkali to the pulping yield and kappa number of the juvenile wood, that it was also very significant for the dosage of alkali and the heat preservation time to the kappa number of the mature wood. On the same technical conditions of pulping,the pulp of the juvenile wood is higher in yield and lower in kappa number and degree of polymerization than that of the mature wood.

Key words: Populus simonii×P.nigra, juvenile wood, mature wood, fiber morphology, pulping property