酚化木质素基酚醛树脂的制备及胶合性能研究

Preparation and Bonding Performance of Phenolated Lignin-Based Phenolic Resin

关键词:  工业木质素  酚化改性  酚醛树脂  胶合强度  烟梗粉

Key Words:industrial lignin  phenolation modification  phenolic resin  bonding strength  TSP

摘要:以工业木质素为原料，经酚化改性制备酚化木质素基酚醛树脂（PKL-PF），并对其胶合性能进行评价。采用L9正交试验优化了水、NaOH及F/P（质量比）工艺参数，并对树脂结构、热行为和流变性能进行表征。结果表明：酚化处理使木质素Mn由14214 Da降至7818 Da，PDI由1.97降至1.60；较优工艺条件为H2O 3.0 g、NaOH 0.6 g、F/P（质量比）1.3。制备的树脂具有明显固化放热和剪切变稀特性。在140℃、施胶量140 g·m-2、热压11 min下，胶合试件干、湿强度分别达5.48 ± 0.36 MPa和4.96 ± 0.52 MPa，均高于0.7 MPa参考值；添加烟梗粉（TSP）后，胶合强度虽有所下降，但仍高于0.7 MPa参考值。本研究为造纸副产物木质素及烟草废弃物的协同利用提供了新途径。

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.