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以乙二醇(EG)为溶剂,三聚氰胺(M)和多聚甲醛(F)为主要原料,氢氧化钾和三乙醇胺为催化剂,合成了三聚氰胺-甲醛(MF)树脂。采用红外光谱(IR)、高效液相色谱(HPLC)、核磁共振(13C-NMR)、热重分析等对EG在MF树脂中的反应机理以及MF树脂的热性能进行了分析。研究表明:乙二醇可以与羟甲基化后的三聚氰胺反应,形成亚甲基桥和醚键结构。当m(EG)∶m(M+F)=0.6∶1、n(F)∶n(M)=2.5∶1、pH值为9~10、反应温度为95℃时,合成的MF树脂固体质量分数高(90.2%)、游离甲醛低(0.51%)、储存稳定性好(>240 d)。树脂的热失重温度约为345℃,800℃残炭率为17.24%。
Melamine-formaldehyde (MF) resin was synthesized by using ethylene glycol (EG) as solvent, melamine (M) and paraformaldehyde as main raw materials, potassium hydroxide and triethanolamine as catalysts. The reaction mechanism of EG in MF resin and the thermal properties of MF resin were analyzed by infrared spectroscopy (IR), high performance liquid chromatography (HPLC), nuclear magnetic resonance (13C-NMR) and thermogravimetric analysis. Studies have shown that ethylene glycol can react with methylolated melamine to form methylene bridges and ether linkages. The MF resin solid synthesized when m (EG): m (M + F) = 0.6:1, n (F): n (M) = 2.5:1, pH value was 9-10 and reaction temperature was 95 ℃ High mass fraction (90.2%), low free formaldehyde (0.51%), good storage stability (> 240 d). The temperature of the resin is about 345 ℃, and the carbon residue rate at 800 ℃ is 17.24%.