间二甲基苯甲酸的结晶提纯

Purification of 3,5-dimethyl benzoic acid by crystallization

采用冷冻结晶和重结晶的方法从均三甲苯氧化液中提取间二甲基苯甲酸,研究了冷冻结晶温度和陈化时间对粗产品收率的影响,采用正交试验主要考察了pH值、结晶温度和陈化时间对重结晶收率、产品酸度和熔点的影响。通过极差分析得到影响产品收率的主要因素以及优化的结晶工艺,间二甲基苯甲酸的结晶收率达81 8%。

3,5dimethyl benzoic acid was obtained from mesitylene oxidation products by crystallization and recrystallization. Based on experiments with the cross design,the effects of pH,crystallization temperature and aging time on the yield of recrystallization, the acidity and melting point of product were mainly investigated. An optimized technological condition and the main factor were obtained. Under the suitable conditions, the yield and purity of 3,5dimethyl benzoic acid were 81.8% and 98% respectively.