热重分析法测定氟唑活化酯的饱和蒸气压

基于自由蒸发过程的Langmuir关系,利用梅特勒-托利多TGA/DSC1/1100LF型热重分析仪,建立采用热失重法快速测定化合物氟唑活化酯的低温饱和蒸气压的方法。采取阶梯升温方式,先在测定温度范围内较低的温度点恒温一定时间,获得满足测定精度所需要的质量损失,升温到下一温度进行测定,直至所需的最高温度。氟唑活化酯25℃时的饱和蒸气压为3.31×10^(-4)Pa。结果表明,利用热重法测定化合物的较低蒸气压,是传统蒸气压测定方法的很好补充,其结果与文献数据符合较好。测定方法系统误差低于1%。

Determination of the Saturated Vapor Pressure of Fluorine Azole Active Ester by Thermogravimetric Analysis

Based on the Langmuir relationship of free evaporation process, using the Mettler - Toledo TGA/DSC1/1100LF thermogravimetric analyzer, we established the thermogravimetric method which was used to rapidly determine the saturated vapor pressure of effective component of fluorine azole activated ester at low temperatures. The heating was carried step by step that, at first obain the measurement accuracy required by the quality loss, it needs to hold the measuring temperature range with low constant temperature for a period of time, then raise up to the next higher temperature until to the required highest temperature. Using this method, we obtained the saturated vapor pressure of fluorine azole active ester which is 3.31 × 10-4Pa at 25℃. The results showed that the thermogravimetric method for determination of compounds with low vapor pressure was a good complement of traditional method. The determination results coincide well with the literature data, and the measurement system error is less than 1%.