L-Cys/EGDE对水解老化和光老化真丝织物的加固效果

采用L-半胱氨酸(L-Cys)和乙二醇二缩水甘油基乙醚(EGDE)作为加固材料,分别对水解老化和光老化真丝织物进行加固处理,为脆弱丝绸文物的加固保护提供简便而有效的技术方法。水解老化样品在加固后的断裂强力由1.9 N±0.3 N提高到18.0 N±0.4 N,断裂伸长从3.0 mm±0.5 mm提高到14.0 mm±0.5 mm;而光老化样品加固后断裂强力由1.8 N±0.3N提高到4.1 N±0.5 N,断裂伸长保持1.0 mm±0.3 mm不变。通过热重分析、13C固体核磁共振表征发现,水解老化样品加固后的热稳定性有所提高,分子结构有所变化;而光老化样品加固后的热稳定性及分子结构都没有发生明显变化。氨基酸分析证明真丝织物在光老化处理后,可以与EGDE反应的酪氨酸(Tyr)、组氨酸(His)的含量大大降低,造成反应位点的大量减少,因此与水解老化样品的加固效果悬殊。将真丝织物水解老化样品、光老化样品的丝蛋白氨基酸组成及含量与文物样品进行比较发现,水解老化样品的丝蛋白氨基酸组成及含量与文物样品更为接近,因此,可利用该加固方法对脆弱丝绸文物进行加固保护。

The Consolidation Effect of L-Cys/EGDE to Hydrolysis-aged and Light-aged Silk Fabrics

In order to provide a simple and effective technological measure for consolidation and protection of fragile silk fabric relics,a consolidation experiment was conducted to silk fabrics aged by hydrolysis and light treatment with L-cystine(L-Cys) and ethylene glycol diglycidyl ether(EGDE) as consolidation material.Breaking strength of the sample aged by hydrolysis was increased from 1.9 N±0.3 N to 18.0 N±0.4 N,and breaking elongation of the sample was increased from 3.0 mm±0.5 mm to 14.0 mm±0.5 mm.Breaking strength of the sample aged by light treatment was increased from 1.8 N±0.3 N to 4.1 N±0.5 N,and breaking elongation of the sample remained at 1.0 mm±0.3 mm.The results of thermogravimetric analysis and 13C CP/MAS NMR indicated that thermal stability of the sample aged by hydrolysis was improved and molecular structure was changed;while the sample aged by light treatment was unchanged in both thermal stability and molecular structure.Amino acid analysis presented that content of tyrosine and histidine,which can form steady chemical bonding with EGDE,was redu-ced greatly in the sample aged by light treatment,leading to its greatly different consolidation effect with the sample aged by hydrolysis.Comparing silk samples aged by hydrolysis and light treatment with silk fabric relics displayed that the amino acid composition and content of sample aged by hydrolysis was more approximate with that of silk fabric relics.Therefore,L-Cys/EGDE consolidation method is recommended for reinforcement and protection of fragile silk fabric relics.