目的 得到一种低温快速固化的潜伏性双氰胺固化剂。 方法 利用红外光谱对合成的新型双酚 A 型酚醛树脂改性双氰胺潜伏性固化剂的结构进行表征,研究双氰胺和酚醛不同配比对固化漆膜性能的影响,采用示差扫描量热(DSC)分析研究改性后固化剂的活性、用量及固化温度。 结果 双氰胺和酚醛较好的摩尔比为 0. 6 : 1,改性固化剂的最佳用量为 30% (相对环氧树脂的质量分数),改性后的恒温固化温度为 127 ℃ 。 结论 该配方合成的双酚 A 型酚醛树脂改性双氰胺固化剂具有最好的综合性能。

Objective To obtain a latent, low-temperature and fast curing dicyandiamide agent. Methods A new latent curing agent of dicyandiamide modified by bisphenol A type phenolic aldehyde resin was synthesized and the structure was characterized by FTIR spectra. The impact of dicyandiamide dosage on product performance was investigated. The activity of the modified curing a- gent, the dosage and the curing temperature were studied with differential scanning calorimetry (DSC). Results The results showed that the suitable molar ratio of dicyandiamide and phenolic aldehyde was 0. 6 : 1, the optimal dosage of the modified curing agent was 30% (relative to the epoxy resin mass fraction), and the constant curing temperature after modification was 127 ℃. Conclu- sions The resulting curing agent of bisphenol A phenolic resin modified dicyandiamide exhibited the best comprehensive perform- ances.