硫酸铵与氯化铵对脲醛树脂胶粘剂性能影响的比较

测定了用硫酸铵与氯化铵固化的脲醛树脂胶粘剂的使用性能和胶合强度,发现在0.5％～2.5％范围内,相同量的硫酸铵和氯化铵对固化时间、pH值、粘度、适用期和胶层剪切强度等的影响无显著差异;2种固化剂所需的调制设备、工艺条件相同,价格相近。由于含氯废旧人造板的燃烧处理可能导致二恶英的生成,建议我国人造板企业以硫酸铵代替氯化铵,以消除一个潜在的污染源,提高产品的环保性,避免今后人造板和板式家具出口遭遇绿色贸易壁垒。

Comparison of the Influences of Ammonium Chloride and Ammonium Sulphate on the Properties of Urea-Formaldehyde Adhesives

Working performances and bonding strength of urea-formaldehyde (UF) adhesives were measured, with NH4Cl or (NH4)2SO4 as hardener. Both the ammonium salts are effective for curing UF and yield glue-joints with similar performances. Their effects on the pH,gelation time and viscosity are practically identical at the same amounts of addition and the same temperatures. Moreover, both of them can be easily handled in the same way and with the same cost effectiveness. As the combustion of waste boards containing chlorine is suspected to cause the formation of poisonous dioxin, the authors of this paper suggest that the manufactures of wood-based panels in China substituts (NH4)2SO4 for NH4Cl in order to eliminate a potential pollution source and to avoid encountering trade barriers of green protectionism in the exportation of UF bonded wood-based panels and related products.