双氰胺甲醛缩聚反应机理和强放热现象研究

Mechanism of the condensation reaction of dicyandiamide and formaldehyde and its apparent heat releasing phenomenon

在分析已有双氰胺甲醛缩聚反应机理的基础上,提出了一种新的反应机理,认为多个双氰胺分子可以通过氰基与胺基反应生成的亚胺基键而生成高分子聚合物,并通过键能计算证明该反应是一个放热反应,其反应放热量与试验中测得的升温温度相符,该机理可以合理地解释双氰胺甲醛缩聚物制备过程中剧烈的放热升温现象。

A new mechanism of the condensation reaction of dicyandiamide and formaldehyde is presented based on analyzing the prior mechanisms. This new mechanism holds the opinion that many dicyandiamide molecules can form a macromolecule by the reaction,which with an imine group formed and is an exothermal reaction confirmed by the bond energy,between the cyanogen group of a dicyandiamide molecule and the amine group of another dicyandiamide group. The bond energy,which causes the apparent heat releasing phenomenon occurred during the preparation of dicyandiamide-formaldehyde condensation polymer,calculated from the new reaction equation is in accordance with the enhanced temperature.