木质素改性脲醛树脂胶粘剂合成工艺及性能研究

Study on synthesis process and properties of urea-formaldehyde resin adhesive modified by lignin

以木质素作为改性剂,采用正交试验法探讨了n(甲醛)∶n(尿素)、木质素加入量和木质素加入时间对UF(脲醛树脂)胶粘剂的游离甲醛含量和胶接强度的影响,并优选出制备改性UF胶粘剂的最佳工艺条件。结果表明:当n(F)∶n(U)=1.6∶1、w(木质素)=40%(相对于尿素质量而言)和前期加入木质素时,UF胶粘剂的游离甲醛含量(0.052 8%)满足室内装饰装修材料用胶粘剂中有害物质限量要求(GB 18583—2001)、胶接强度为6.65 MPa且耐水性明显提高。

With lignin as a modifier, the influences of molar ratio of n （formaldehyde） ：n （urea）, contents and adding time of lignin on free formaldehyde content and bonding strength of UF（urea-formaldehyde resin） adhesives were discussed by orthogonal experiment, and the optimal process conditions of preparing modified UF adhesives were preferred. The results showed that the free formaldehyde content（0.052 8%） in UF adhesives could meet GB 18583--2001 requirement for limiting contents of harmful substances,which were exist in adhesives for interior decoration,bonding strength was 6.65 MPa,and water-resistance was obviously enhanced when molar ratio of n（F）：n（U） was 1.6：1 ,mass fraction of lignin was 40% in urea,and lignin was introduced into system at prophase.