胶合板用脲醛树脂胶粘剂的纳米改性

Nano-modification of urea formaldehyde resin adhesive for plywood

以MMT(蒙脱土)或OMMT(有机蒙脱土)作为改性剂,两者分别在UF(脲醛树脂)合成的不同阶段(加成阶段、缩聚阶段和缩聚后期)中以同一投料比引入体系中,制备相应的改性UF胶粘剂。研究结果表明:当n(F):n(U)=1.2:1、w(MMT或OMMT)=2%(相对于尿素总质量而言)时,MMT和OMMT的引入,能使相应改性UF胶粘剂的某些性能(如黏度、固含量、胶接强度和固化时间等)增加、游离甲醛含量降低;OMMT的改性效果优于MMT,并且OMMT在加成阶段投入时降醛效果明显,在缩聚阶段投入时补强效果明显。

With a M MT（montmorillonite） or an O MMT （organic montmorillonite） as modifiers, the corresponding modified UF （urea formaldehyde resin ） adhesives were prepared when these modifiers with same feeding ratio were introduced respectively into different synthesis stages （such as polyaddition, polycondensation and post- polycondensation） of UF. The research results showed that the adding MMT or OMMT could increase some properties （such as viscosity, solid content, bonding strength, curing time and other properties） and could reduce free formaldehyde content of corresponding modified UF adhesive when molar ratio of n（F）：n（U） was 1.2：1, mass fractions of MMT or OMMT were all 2% in total urea. The modified effect of OMMT was better than that of MMT, and the OMMT had obviously debasing aldehyde effect at polyaddition into system and obviously reinforcing effect at polycondensation into system.