Monomer recovery from polyimide hydrolysis in high-temperature water was investigated using batch-type reactors with respect to the effects of reaction time, temperature, and sodium hydroxide concentration. Direct observation of the polyimide decomposition in high-temperature water revealed that gas bubbles were produced above 423 K and polyimide dissolution occurred above 573 K. The monomers 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid, PMA) and 4,4ʹ-diaminodiphenyl ether (4,4ʹ-oxydianiline, ODA) were produced in the early stages of the reaction. The generated PMA decomposed to form carbon dioxide after a reaction time of 10 min at 573 K, while the ODA was relatively stable. Moderate temperature and sodium hydroxide concentration promoted polyimide hydrolysis, whereas overcracking of the polyimide occurred in the presence of excess sodium hydroxide at high temperature. A reaction time of 5 min and alkali concentration of 22 mmol/kg were found to be the optimal conditions for monomer recovery at 573 K.

关于反应时间，温度和氢氧化钠浓度的影响，使用间歇式反应器研究了在高温水中从聚酰亚胺水解中回收单体的方法。对聚酰亚胺在高温水中的分解进行的直接观察表明，在423 K以上时会产生气泡，在573 K以上时会发生聚酰亚胺溶解。1,2,4,5-苯四甲酸（均苯四酸，PMA）和4,4ʹ -二氨基二苯醚（4，4′-羟二苯胺，ODA）在反应的早期阶段产生。在573 K下反应10分钟后，生成的PMA分解形成二氧化碳，而ODA相对稳定。温和的氢氧化钠浓度促进了聚酰亚胺的水解，而在高温下，在过量氢氧化钠的存在下，聚酰亚胺过度裂解。发现反应时间为5分钟和碱浓度为22 mmol / kg是在573 K下回收单体的最佳条件。