氢过氧化物对皮革中Cr(Ⅲ)转化为Cr(Ⅵ)的影响

Influence of Hydroperoxide on Oxidation of Cr (Ⅲ) to Cr (Ⅵ)

使用过氧化叔丁醇(CH3)3C—OOH模拟皮革生产中使用的不饱和加脂剂(或油脂)因氧化而产生的氢过氧化物ROOH,室温下通过使用过氧化叔丁醇分别与三氯化铬及标准铬粉溶液作用一定时间,测定体系中的六价铬含量,来研究氢过氧化物对皮革中Cr3+转化为Cr6+之间的关系。试验表明:氢过氧化物的替代物—过氧化叔丁醇,不论在三氯化铬体系还是在铬粉鞣剂体系下,都可以将Cr3+氧化成Cr6+,这可以间接证明在成品革中,由不饱和加脂剂氧化而产生的氢过氧化物,能将皮革中存在的游离Cr3+氧化成Cr6+。皮革加脂剂氧化产生的氢过氧化物越多,则成革中游离的三价铬被氧化的越多,相应六价铬的含量也越多。

Instead of hydroperoxide in lipids, tert - butyl hydroperoxide solution was used as a reacting reagent, because of its character similar to the product - hydroperoxide resulting from the autoxidation reaction of lipids. Tert - Butyl hydroperoxide was put in soluble Cr（ Ⅲ ） solution in room temperature. Then, by determining the content of the Cr （ VI ） at regular intervals, the experiment will demonstrate the oxidation mechanism of Cr （ Ⅲ ） to Cr （VI） and the relation between them. It shows that Cr （ Ⅲ ） could be oxidized to Cr （ VI ） by tert - Butyl hydroperoxide both in chromium chloride systerm and in chrome powder. The more the hydroperoxide resulting from the autoxidation of fatliquor the more Cr （ Ⅲ） oxidized to Cr （ Ⅵ）.