Dark animal fiber is bleached to satisfy the demand of color diversity for clothing. Comparing with frequently-used Fe catalyzed HO (Fe/HO) bleaching method, the ammonium persulfate (APS)/HO bleaching method based on the persulfate (PDS)-based advanced oxidation process is considered to be an environmentally animal fiber bleaching method, which is advantageous in high efficiency, heavy metal-free and low damage. However, the degradation mechanism of eumelanin of APS/HO bleaching method remains to be explored. Herein, standard eumelanin (SM) which has higher purity of eumelanin was used as reaction model, and SM was proved to degrade into five soluble oligomers by chemical structure analysis. Therefore, a new degradation pathway of eumelanin in APS/HO solution was simulated and proposed by in vitro experiment. In addition, the yak wool fiber was low damage by testing the fiber structure before and after bleaching. The dyeing property of yak wool fabrics had no effect on APS/HO bleaching. This investigation of degradation products provides new insights into the bleaching mechanism of APS/HO environmentally dark animal fiber bleaching method.

中文翻译：

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过硫酸盐/过氧化氢一步漂白动物纤维的方法：真黑色素的降解机理

深色动物纤维经过漂白处理，满足服装色彩多样性的需求。与常用的Fe催化H2O（Fe/H2O）漂白方法相比，基于过硫酸盐（PDS）高级氧化工艺的过硫酸铵（APS）/H2O漂白方法被认为是一种环保的动物纤维漂白方法。具有效率高、不含重金属、损伤低等优点。然而，APS/H2O漂白方法对真黑色素的降解机制仍有待探索。本文以真黑素纯度较高的标准真黑素（SM）为反应模型，通过化学结构分析证明SM降解为5种可溶性低聚物。因此，通过体外实验模拟并提出了APS/H2O溶液中真黑色素的新降解途径。另外，通过测试漂白前后的纤维结构，发现牦牛毛纤维损伤程度较低。牦牛毛织物的染色性能对APS/HO漂白没有影响。此次降解产物的研究为APS/H2O环保深色动物纤维漂白方法的漂白机理提供了新的见解。