用热分析技术研究巴比妥的动力学性能

用热分析法研究巴比妥的热失重过程并讨论升温速率对巴比妥热解过程的影响.结果表明,巴比妥热失重温度范围为温度160～220℃,质量失重率〉97%.巴比妥的分解过程分两个阶段进行,分解率α在0.2～0.45,用等转化率迭代方法求得失重的Ea=（148.468±0.674）kJ/mol,在0.55～0.90,求得Ea=（102.970±1.004）kJ/mol,巴比妥的分解过程在分解率α为0.45～0.55相互重叠,用主曲线法确定巴比妥失重过程两个阶段的最可几机理函数分别为G（α）=-ln（1-α）]3/4和G（α）=-ln（1-α）]1/2.

Study on the pyrolysis kinetics of Barbital using thermal analysis technique

The thermal mass-loss of barbital was investigated by thermogravimetry technique.The influence of pyrolysis was discussed in different heating rate.The resnlts show that the mass-loss temperature of Barbital was in the range of 160~220℃,the mass-loss rate was found greater than 97%.The decomposition of the process of Barbital was divided into two stages,in the first stage,the iterative iso-conversional method was applied to concluded the apparent activation energy Ea when the mass-loss rate was in the range of 0.20~0.45,the apparent activation energy was(148.468±0.674)kJ/mol.In the second stage,the same method was applied to concluded the apparent activation energy Ea when the mass-loss rate was in the range of 0.55~0.90,the apparent activation energy was(102.970±1.004)kJ/mol.The decomposition of the process of Barbital overlapped each other in the range of 0.45~0.55.The most probable mechanism functionG(α)of two stages was determined by master plots method,and G(α)=-ln(1-α)]3/4 and G(α)=-ln(1-α)]1/2.