2，5-二羟基对苯二甲酸的合成研究

Study on the Synthesis of 2,5-Dihydroxyterephthalic Acid

PIPD纤维是一种新型液晶芳杂环聚合物纤维,它是由2,3,5,6-四氨基吡啶(TAP)和2,5-二羟基对苯二甲酸(DHTA)两种单体制得,研制的目的是合成单体DHTA,并对其进行分析表征。用对二甲苯为溶剂、对苯二酚和碱金属碳酸盐及碱金属碳酸氢盐作为原料,在N_2的气氛和一定压力下可制备出2,5-二羟基对苯二甲酸,通过HPLC、FT-IR、DSC、元素分析和核磁等对产物结构和纯度进行表征,发现产物结构正确,且纯度可达99.5%。实验结果表明,该工艺路线可行,产物纯度高,重复性好,是一个工艺简便、成本低的好方法。

As a new type of liquid crystal heterocyclic polymer fiber, PIPD is synthesized with 2,3,5,6 -tetraaminopyridine （TAP） and 2,5 -dihydroxyterephthalic acid（DHTA）. 2,5 -dihydroxyterephthalic acid（DHTA） is introduced which prepared from hydroquinone, alkali metal carbonate and alkali metal hydrogen carbonate with xylene as the solvent in a nitrogen atmosphere and a certain pressure. The products are characterized by HPLC, FT- IR, DSC, elemental analysis and HNMR. The results showed that the 99.5% pure monomer can be synthesized by this method, and it is a simple and cheap method due to the feasible process and higher yield.