by Mavrantonis P. and Zoumpoulakis L.
The natural aging of paper is a complex process of chemical, physicochemical, biological and mechanical pro-cesses that are usually not independent of each other but interact with each other. These processes are accel-erated or slowed down by the microenvironment of the paper (humidity and temperature), depending on the presence or not of alkaline protection CaCO3 imparted by the chemical treatment. The aim of this work is to investigate for first time by X-ray Photoelectron Spectroscopy (XPS) and then by Fourier Transform Infrared Spectroscopy (FTIR) the effectiveness of these methods applied to cellulose chain decay by natural (rather than artificial) aging in archival paper and whether there is an improvement on the microstructure and microme-chanical properties of paper in samples from the Historical Archive of the Communist Party of Greece. This will also contribute to a better understanding of the causes and mechanisms of wear and consequently to their more effective treatment. The analysis of the samples and the processing of the results showed that the cellu-lose macromolecule is stabilized in humidity and temperature conditions that do not favor its acid hydrolysis (the main mechanism of decomposition in the natural aging of paper), the endogenous and exogenous factors of its destruction (mainly acids ) are weakened, neutralized after the physicochemical preservation interven-tions, the percentages of pure α-cellulose, hemicelluloses and lignin as well as its crystalline and amorphous regions remain stable and slightly improved in some samples.