Acid-catalysed hydrolysis and oxidation are the main pathways of paper degradation. During degradation, organic acids accumulate in the paper, which increases the acidity of the paper and accelerates hydrolysis. The consequences of these two processes can lead to the loss of the written cultural heritage.
Methanoic, ethanoic, lactic, succinic, glycolic, oxalic, and other acids or their anions are found in historical papers. Although these are weak acids, their effects can be considerable due to their high concentration.
In this work, I monitored the concentration of selected acids in differently artificially aged
historical paper samples using ion chromatography. During degradation, I monitored the colour of the paper and measured the differences in the pH of the paper at the end of the experiment.
Based on the obtained data, I investigated the influence of the experimental conditions (temperature, relative humidity, duration of the experiment) on the concentration of the formed acids, colour, and pH of the paper. acids formed and the colour of the paper.
I compared two different methods of accelerated degradation and found that the conventional method, where the sample is exposed to an airflow, underestimates the change in colour and pH. The differences in the concentration of organic acids are not significant. I evaluated the impact of lignin on the measured parameters.
|
