不同浓度硫酸对纸张老化性能影响的初步研究

A Preliminary Study on the Eff ect of Diff erent Concentrations of Sulfuric Acid on the Aging Properties of Paper

纸质文献信息书写所用的蓝黑墨水等均含有硫酸等酸性物质,这些酸性物质是造成纸张老化的重要因素之一。研究采用2%、4%、6%、8%、10%硫酸对宣纸、毛边纸、报纸三种纸张进行浸泡10天,分别测试纸张的色差、抗拉强度和纤维的显微结构变化。结果表明,随硫酸浓度增高,三种纸张的明暗L值都变小,纸张的颜色在慢慢变暗,黄绿值a值逐渐增大,颜色泛黄,总色差ΔE增大,颜色变化明显;最大抗拉强度下降,强度降低。显微结构表明纸张纤维在硫酸作用下发生断裂、变短,纸张老化、劣化,硫酸浓度越高,纤维断裂越短,导致纸质文献的文物价值和文献价值的损毁。

Acidic substances such as sulfuric acid,which is contained in writing materials,is one of the important factors causing paper aging.Xuan paper,edging paper and newspaper were soaked in 2%,4%,6%,8%and 10%sulfuric acid for 10 days in this study.The properties of the color diff erence,tensile strength and microstructure of fibers were tested respectively.The results showed that the L value which expresses light-shade of the three kinds of paper decreased,with the increase of sulfuric acid concentration,the color of the paper gradually darkened.Simultaneously,the a value which indicates yellow-green gradually increased,the color became more yellow.The total color diff erenceΔE increased,the color change was obvious.The maximum tensile strength also decreased with the increase of sulfuric acid concentration.The paper fiber was broken and shortened under the action of sulfuric acid,the higher the concentration of sulfuric acid was,the shorter the fiber was broken.The aging and deterioration of papers in acidic environment has induced the destruction of the cultural heritage value and literature value.