双氧水氧化脱毛机理及工艺条件优化

观察了双氧水对毛的作用，并测定了脱毛过程中双氧水对生皮及皮胶原的影响。数据显示，毛的破坏是双氧水和NaDH共同作用的结果。脱毛时，毛根首先被溶解，因而有利于保毛脱毛法的实施。在碱性环境中，双氧水不会对生皮产生破坏作用，反而显示出对皮胶原纤维有一定的保护作用，这种保护作用可能是由于双氧水引发了胶原纤维间的交联反应，它导致成革抗张强度提高、伸长率降低。与传统Na2S脱毛相比，双氧水脱毛后，裸皮的等电点更高，可能是由于双氧水的氧化作用导致皮胶原衍生出了更多的阴离子基团，如羧基。这一变化使双氧水脱毛后铬鞣革的铬含量增加。基于这些研究结果，提出了双氧水毁毛脱毛法和双氧水保毛脱毛法的优化工艺条件。

The Mechanism of Oxidative Unhairing Using Hydrogen Peroxide and Optimization of the Process

The research includes details of hair removal from hide and the influence of hydrogen peroxide on hide/collagen during unhairing process. The results showed that destruction of hair was led by cooperative effect of hydrogen peroxide and sodium hydroxide. The dissolution of hair first happened at hair root, which favors implementation of hair saving system. It was also found that the oxidative effect of H 2 O 2 causes slight protection function of collagen in alkaline medium ( probably, due to cross-linking reaction of collagen induced by H 2 O 2 ), which is one of the reasons leading to higher tensile strength and lower elongation rate of resultant leather. Isoelectric point of the hide unhaired with H 2 O 2 was lower than that using conventional Na 2 S unhairing process, due to that more carboxyl or anionic groups were probably derived. Therefore, the chrome tanned leather employing H 2 O 2 unhairing process exhibited higher Cr 2 O 3 content. Based on these observations, the optimal conditions for undertaking H 2 O 2 unhairing, including hair dissolution and hair recovery processes, were presented.