摘要
价键理论根据鞣剂与胶原活性基团形成配位键的强弱 ,解释各种无机鞣剂鞣革性能的差异。价键理论认为 :Cr( )与 Al( )相比 ,由于 Cr( )形成的配合物是内轨型配合物 ,而 Al( )形成的配合物是外轨型配合物 ,因此铬配合物更稳定 ,Cr( )鞣革比 Al( )鞣革耐湿热稳定性好 ,收缩温度高 ;革收缩时配位键发生断裂。但对收缩过程的热力学研究发现 ,胶原或革收缩时配位键并未断裂 ,而是氢键破坏 ,收缩温度与收缩反应的活化能有关。因此协同单元理论认为 :革收缩过程是一个动力学过程 ;收缩温度与协同单元的大小有关。协同单元理论对各种鞣剂的鞣性差异给出了比较满意的解释。
The bonding theory explains the difference of hydrothermal stability of leathers tanned by various mineral-tanning agents according to their bond strength to collagen. Thus, Cr(Ⅲ)tanned leather has higher shrinkage temperature than Al(Ⅲ)does since the former forms inner orbit complex and the later forms outer orbit complex when interacting with collagen. And consequently, heat denaturation of leather is caused by breaking of bonds. But researching into the thermodynamics of shrinking, it is found that the process of heat denaturation of collagen or leather is caused by the breaking of hydrogen bonds, rather than a breakdown of the tannin-collagen bonds. Therefore, the cooperating units theory is proposed, that is, the denaturation of collagen or leather is a kinetics process, and shrinkage temperature depends on the size of 'cooperating units' formed during tanning. This theory can give relatively satisfactory explain for the difference of various tanning agents.
出处
《中国皮革》
CAS
北大核心
2002年第13期18-22,共5页
China Leather
基金
教育部重点项目"双氧水脱毛和高 p H铬鞣的机理及其串联应用的工艺平衡 (项目编号 :1 9990 60 2 5 )"资助研究
关键词
价键理论
协同单元理论
鞣制机理
发展
皮革
胶原
leather collagen tanning mechanism bonding theory cooperating units theory
