三聚氰胺改性脲醛树脂胶黏剂的固化性能

Curing properties of melamine MUF resin adhesives

以三聚氰胺为改性剂,通过碱-酸-碱工艺合成了低游离甲醛含量的三聚氰胺改性脲醛树脂胶黏剂,研究了NH_4Cl用量对三聚氰胺改性脲醛树脂固化性能及固化物结构的影响。结果表明:三聚氰胺质量分数为2.5%,游离甲醛质量分数为0.14%,且w(NH_4Cl)为2.0%时对改性脲醛树脂的固化效果最佳。X射线衍射测试证实了固化物内部晶态与非晶态共存;拉曼光谱分析从结构上进一步证实了固化物结构上的差异性。

Melamine modified urea-formaldehyde（MUF） resin adhesives in low free formaldehyde content were synthesized via alkali-acid-base process with melamine as modifier. The effects of the amount of NH4Cl on the curing properties and cured structure of the modified resins were investigated. The results show that the optimally cured MUF resin is obtained when the mass fraction of melamine, free formaldehyde and NH4Cl are 2.5%, 0.14%, and 2.0% respectively. The XRD results confirm that the crystalline and amorphous coexist in the cured products. Raman spectroscopy further confirms the structural differences among the cured products.