三聚氰胺添加方式对三聚氰胺改性脲醛树脂胶合纤维板性能的影响

Effect of Feeding Modes of Melamine on Properties of Fiberboard Glued with MUF Adhesive

研究了分次添加三聚氰胺的三聚氰胺改性脲醛树脂(MUF)胶黏剂对中密度纤维板内结合强度、弹性模量和静曲强度、吸水厚度膨胀率与甲醛释放量的影响。结果表明:分次添加有利于提高纤维板的物理力学性能,降低吸水厚度膨胀率,对E1级板材的甲醛释放量影响不大。因为后期加入的三聚氰胺,一方面提高了MUF与纤维的反应能力,另一方面起到了防水剂的作用。最优配方为随第一次尿素一起投入总质量50%的三聚氰胺,剩余三聚氰胺随第二次尿素加入。

We studied the effect of feeding modes of melamine in preparing melamine-urea-formaldehyde（ MUF） adhesive on internal bonding strength,modulus of elasticity and modulus of rupture,thickness swelling and formaldehyde emission of fiberboard. The addition of melamine with several times improved the physical and mechanical properties of fiberboard,reduce thickness swelling,and had little effect on formaldehyde emission（ E1 grade）. Optimal formulation was adding 50%of the total melamine with urea firstly,and the remainder was added with urea later,because it would improve the crosslinking reaction between MUF resin and wood fiber,and waterproofing agents of melamine resulted from the melamine added in the later stage.