针对脲醛树脂胶粘剂中游离甲醛含量偏高的问题,研究了尿素/甲醛摩尔比对树脂中游离甲醛含量的影响,选用木质素作为脲醛树脂的改性剂。分析了木质素添加量对树脂中游离甲醛的影响以及木质素的纯度对游离甲醛的捕捉效果。结果表明,摩尔比越低,树脂中的游离甲醛含量越高;木质素通过苯-乙醇的浸提,有助于提高木质素对游离甲醛的捕捉能力。当树脂中M2的含量为尿素的30%时,脲醛树脂的胶合强度为5.91 Mpa,游离甲醛含量为0.094%,均达到最佳值。此外,木质素对脲醛树脂的耐水性能也有明显的改善。 In view of the high content of free formaldehyde in the urea-formaldehyde resin adhesive, the effect of urea / formaldehyde molar ratio on the content of free formaldehyde in the resin was studied. Lignin was chosen as the modifier of urea-formaldehyde resin. The effects of the amount of lignin on free formaldehyde in the resin and the capture effect of free formaldehyde on the purity of lignin were analyzed. The results showed that the lower the molar ratio, the higher the content of free formaldehyde in the resin. The leaching of lignin through benzene-ethanol helps to improve the capture ability of lignin to free formaldehyde. When the content of M2 in the resin is 30% of the urea, the bonding strength of the urea-formaldehyde resin is 5.91 Mpa and the free formaldehyde content is 0.094%, both of which reach the optimum value. In addition, lignin on the water-resistant properties of urea-formaldehyde resin has also been significantly improved.