均苯四酸二酐凝华结晶精制的最佳条件研究

研究了均苯四酸二酐（简称均酐或PMDA）凝华结晶精制的最佳条件,并以均酐在定温下的平衡蒸汽压为基础,推导出凝华结晶条件数学关系式．该式把氧化反应的空速,气相组成及捕集温度等工艺参数与捕集率关联起来,并制作出捕集温度对均酐凝华结晶效率和均酐纯度关系曲线图．同时讨论了拉乌尔数学关系式在处理本体系的适应范围．指出在低捕集率情况下,引入修正项后的拉乌尔数学关系式才能与实验值吻合．

Study on the Optimal Conditions for Sublimate Crystallization Refining of Pyromellitic Dianhydride

Abstract：In this paper the optimal conditions for sublimate crystallization refining of pyromellitic dianhydride （PMDA）was studied, and on the basis of PMDA equilibrium vapor pressure under the eontant temperature, the mathematical correlation for sublimate crystallization conditions was deduced. In this correlation, the space velocity of oxidation reaction, gas components and catching temperature etc. were associated with catching rate, and the relation curve diagram about catching temperature to PMDA sublimate crystallization efficiency and PMDA purity was developed. At the same time, the adaptable range of Raoult＇ s mathematical relation in this dealing system was discussed, and producing deviation reasons about Raouh＇ s mathematical relation dealing this system was initially analyzed. The result shows that Raoult＇ s mathematical relation introduced modifications was just coincided with experiment data under the low catching rate.