Poly(p-phenylene terephthalamide) (Kevlar^®) fibers, with good chemical and mechanical strengths, were hydrolyzed into their constituent p-phenylenediamine and terephthalic acid monomers using supercritical water, subcritical water, and subcritical water with sodium hydroxide. The two monomers recovered from the Kevlar^® fibers were purified using simple extraction and precipitation methods, and the purity of each monomer exceeded 99%. Treatment with subcritical water and sodium hydroxide for 6 h completely decomposed the Kevlar^® fibers, with yields of approximately 95% for each monomer obtained at 250 °C, 4 MPa, and an initial molar ratio of sodium hydroxide to the Kevlar^® unit of five. On the other hand, treatment with subcritical and supercritical water resulted in lower decomposition efficiencies and monomer yields. In addition, the kinetics of Kevlar®-fiber hydrolysis was examined assuming a cylindrical-surface reaction model, and temporal changes in the decomposition efficiencies of Kevlar^® fibers were found to be reproduced well using this model.

聚（p亚苯基对苯二甲酰胺）（凯夫拉尔^®）纤维，具有良好的化学和机械强度，进行水解成它们的组成p使用超临界水，亚临界水，亚临界水与氢氧化钠苯二胺和对苯二甲酸的单体。两种单体从凯夫拉尔回收^®使用简单的提取和沉淀的方法进行纯化的纤维，和各单体的纯度超过99％。治疗亚临界水和6小时氢氧化钠完全分解凯夫拉^®纤维，具有用于在250℃下，4兆帕获得的每个单体和氢氧化钠与芳纶的初始摩尔比约95％的产率^®五个单位。另一方面，用亚临界和超临界水处理导致较低的分解效率和单体产率。另外，检查的Kevlar纤维水解的动力学假设的圆筒表面反应模型，并在芳纶的分解效率随时间的变化^®发现纤维利用该模型再现良好。