六羟甲基三聚氰胺的甲醚化反应机理分析及动力学研究

发布时间：2018-02-09 10:01

  本文关键词： 六羟甲基三聚氰胺 六甲氧基甲基三聚氰胺 醚化反应 动力学　出处：《高校化学工程学报》2016年06期 　论文类型：期刊论文

【摘要】：在硝酸催化下进行六羟甲基三聚氰胺(HMM)与甲醇的甲醚化反应,生成了六甲氧基甲基三聚氰胺(HMMM)。考察了反应过程中甲醇浓度的变化,提出了HMM甲醚化反应的机理并建立了动力学模型。通过实验数据拟合出醚化动力学参数,分析了不同反应温度下醚化度-时间关系。结果表明,该反应是典型的可逆平衡反应,pH=3.5下,当温度由30℃升高至55℃时,甲醚化反应平衡常数由1.17增大至2.79。甲醚化正逆反应速率常数与温度的关系分别为k1=8.54×10~6×exp(-5.39×10~4/RT)与k2=257×exp(-2.79×10~4/RT)。根据van't Hoff方程计算了该甲醚化反应表观反应焓为25.97 k J×mol~(-1),表观反应熵为86.5 J×(mol·K)~(-1)。
[Abstract]:The methoxymethyl melamine (HMMM) reaction with methanol was carried out under the catalysis of nitric acid. The change of methanol concentration during the reaction was investigated. The mechanism of HMM methyl ether reaction was put forward and the kinetic model was established. The etherification kinetic parameters were fitted by experimental data, and the relationship between etherification degree and time at different reaction temperature was analyzed. The reaction is a typical reversible equilibrium reaction at pH 3.5. When the temperature is raised from 30 鈩，

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