| Abstract:Industrial lignin was used as the raw material to prepare phenolated lignin-based phenolic resin (PKL-PF) via phenolation, and its bonding performance was evaluated. An L9 orthogonal experiment was employed to optimize the process parameters, including H2O dosage, NaOH dosage, and F/P mass ratio. The resin structure, thermal behavior, and rheological properties were characterized. The results showed that phenolation reduced the number-average molecular weight (Mn) of lignin from 14214 Da to 7818 Da and decreased the polydispersity index (PDI) from 1.97 to 1.60. The optimal process conditions were H2O 3.0 g, NaOH 0.6 g, and an F/P mass ratio of 1.3. The prepared resin exhibited a distinct curing exotherm and shear-thinning behavior. Under a hot-pressing temperature of 140℃, an adhesive spread of 140 g·m-2, and a pressing time of 11 min, the dry and wet bonding strengths of the bonded specimens reached 5.48 ± 0.36 MPa and 4.96 ± 0.52 MPa, respectively, both higher than the reference value of 0.7 MPa. Although the bonding strengths decreased after the addition of tobacco stem powder (TSP), they remained above the reference value of 0.7 MPa. This study provides a new approach for the synergistic utilization of papermaking by-product lignin and tobacco waste. |