制浆黑液在酚醛树脂胶黏剂中的应用

Application of Pulping Black Liquor in Phenol-formaldehyde Resin Adhesive

关键词:  制浆黑液  酚醛树脂胶黏剂  木质素  游离甲醛  胶合强度

Key Words:pulping black liquor  PF resin adhesive  lignin  free formaldehyde  bonding strength

摘要:制浆黑液中的降解木质素含有酚羟基结构，可以替代部分苯酚制备酚醛树脂。以NaOH为催化剂，采用二次缩聚法制取酚醛树脂胶黏剂。实验表明，当黑液添加量为15%时，胶黏剂的黏度比空白实验增加1倍，游离甲醛含量降低了27%，胶合强度提高了13.2%。红外光谱分析表明，黑液中的木质素与游离甲醛反应生成有羟甲基的物质，该物质能与酚醛树脂胶粘剂中的物质发生反应，从而既降低了甲醛含量又提高了胶黏剂的胶合强度。

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.