| Abstract:Degradated lignin in pulping black liquor has phenolic hydroxyl structure, which can be used in production of phenol resin. The phenol-formaldehyde resin adhesive was prepared by quadric polycondensation process with NaOH as catalyst. The experiments turn out: When the mass fraction of black liquor was 15%, dynamic viscosity of the adhesive has doubled; mass fraction of free formaldehyde was reduced by 27%, bonding strength increased by 13.2%. IR spectrum showed that the lignin in the black liquor reacts with free formaldehyde to produce ring structure material with hydroxyl, condensation between the hydroxyl of ring material and PF adhesive, results in the increase in the free formaldehyde as well as the bonding strength of adhesive. |
