皮革文物的光氧老化机理研究  

A study on the mechanism of photo-oxidation of leather relics

作　　者：雷凯鑫 杨璐[1] LEI Kaixin;YANG Lu(School of Cultural Heritage,Northwest University,Xi’an 710127,China)

机构地区：[1]西北大学文化遗产学院,陕西西安710127

出　　处：《文物保护与考古科学》2024年第4期40-49,共10页Sciences of Conservation and Archaeology

基　　金：国家重点研发计划项目(2019YFC1520701)资助;文物科学技术研究项目(2023ZCK029)资助。

摘　　要：为了探究光照作用下皮革文物的老化机理,本研究采用经人工老化的现代植物鞣制羊皮为模拟样品,使用傅里叶变换红外光谱分析、扫描电子显微镜分析、原子力显微镜分析、色度分析、热重分析等方法,探究了样品在老化过程中微观和宏观上的变化。研究结果表明,光照会导致皮革中氨基酸和植物单宁氧化,进而在1715 cm-1处出现羰基的特征峰。羰基指数随着光照时间的延长而增大,因而可以作为皮革氧化程度的量化指标。芳香族氨基酸和植物单宁氧化会导致皮革变色,且通过拟合可以得到色差随光照时间变化的预测模型。氢键在光照作用下断裂,胶原蛋白分子内无规卷曲相对含量增加到33.14%,证明胶原蛋白三螺旋结构解旋,分子无序性增大,稳定性降低,同时导致部分结晶水释放。此外,皮革内的水分和脂质在光照下流失,使纤维收缩卷曲,空隙增大,同时产生应力,并逐渐积累使皮革表面产生形变。In order to explore the aging mechanism of leather relics under the influence of light,in this study,we used artificially-aged modern vegetable-tanned sheepskin as the simulation samples,and carried out Fourier transform infrared spectrometry,scanning electron microscopy,atomic force microscopy,colorimetric analysis and thermogravimetric analysis to explore the micro and macro changes in the aging process of the samples.The results show that light caused the oxidation of amino acids and tannins in leather,seen by the appearance of a characteristic carbonyl peak at 1715 cm-1.The carbonyl index increased with the extension of light time and thus could be used as a quantitative index of the degree of leather oxidation.Oxidation of aromatic amino acids and vegetable tannins could cause leather discoloration,and a prediction model of color difference changing with light time could be obtained by fitting.When the hydrogen bonds broke under the action of light,the intramolecular random curling content of collagen increased to 33.14%.This proved the unwinding of the triple helix structure of collagen,an increase of molecular disorder,a decrease of stability,and the release of part of the crystalline water.In addition,the moisture and lipids in the leather were lost under the light,which made the fibers shrink and curl,and the gap between fibers increased.At the same time,stress was generated,which gradually accumulated and caused the deformation of the leather surface.

关 键 词：皮革 光照 老化 

分 类 号：K876.9[历史地理—考古学及博物馆学]