环氧粉末涂料的固化机制研究

The Study of Cure Mechanism of a Fusion-bonded Epoxy Powder Coating

  • 摘要: 用丁酮作萃取溶剂, 研究了环氧/双氰胺粉末涂层自由膜在160~230℃温度下经不同时间固化后的萃取固化度, 分析了涂膜固化反应的动力学过程。在研究温度范围内, 固化反应表现出单一的表观激活能。环氧/双氰胺粉末涂料的固化反应相当复杂, 既有环氧基与胺基的加成反应, 又有体系中羟基与氰基的聚合反应。文中讨论了固化反应机理, 澄清了两种反应的相对作用。

     

    Abstract: The degree of cure (DOC) of a new type of epoxy/dicyandiamide powder coatings was detected by using solvent extraction on the free film cured at temperatures from 160℃to 230℃ for different time and the kinetic process was analyzed. The results revealed that the cure reaction yielded a single Arrhenius activation energy (91.4kJ/mol), which indicated that there might be only one overall reaction mechanism in the range of the temperature tested. The cure reaction of epoxy/dicyandiamide powder system was complex, involving two principal reactions between epoxide and amine hydrogen, and between hydroxyl groups and —CN. The cure mechanism was also discussed.

     

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