原位制备混二甲苯磺酸及其催化合成TMPTMA
Synthesis of TMPTMA Catalyzed by Mixed Xylene Sulfonic Acid Prepared in Situ

以工业生产二甲苯的精馏剩余物(主要成分为邻、间、对–二甲苯)和98%硫酸反应制备得到混二甲苯磺酸作为催化剂，以三羟甲基丙烷(TMP)、甲基丙烯酸(MA)为原料，采用共沸酯化法合成三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)。研究了催化剂用量、外加热源温度、反应时间对酯化过程的影响，结果表明最适于本反应的条件为催化剂质量为TMP与MA质量之和的5%、外加热源温度为130℃、反应时间为8小时，在此条件下原料TMP与MA的转化率、反应酯化率均在98%以上。分别采用GC和GC-MS对产品进行了纯度检测和定性分析。通过对比，发现自制混二甲苯磺酸催化效果明显优于98%硫酸、与工业对甲苯磺酸具有几乎相同的催化性能。为解决工业生产二甲苯的精馏剩余物(主要成分为邻、间、对–二甲苯)提供了一种资源化利用思路。
Mixed xylene sulfonic acid was prepared in situ by the reaction of industrial xylene distillation residue (the main components are o-, m- and p-xylene) and 98% sulfuric acid. Trimethylolpropane trimethylacrylate (TMPTMA) was synthesized by azeotropic esterification with trimethylolpropane (TMP) and methacrylic acid (MA) catalyzed by the mixed xylene sulfonic acid. The effects of catalyst dosage, external heat source temperature and reaction time on the esterification process were studied. The results showed that the most suitable conditions for the reaction were that the mass of catalyst was 5%, the external heat source temperature was 130？C and the reaction time was 8 hours. Under these conditions, the conversion and esterification rate of raw material TMP and MA were more than 98%. The purity of the product was detected and qualitatively analyzed by GC and GC-MS. It is found that the catalytic effect of mixed xylene sulfonic acid is obviously better than 98% sulfuric acid, and has almost the same catalytic performance as industrial p-toluenesulfonic acid, which provides a resource utilization idea for solving the distillation residue of industrial production of xylene (the main components are o-xylene, m-xylene and p-xylene).