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1. A study of mechanical properties of papers exposed to various methods of accelerated ageing. Part I. The effect of heat and humidity on original wood-pulp papers

Author

Havlínová, Bohuslava, Katuščák, Svetozár, Petrovičová, Miroslava, Maková, Alena, and Brezová, Vlasta

Subjects
*PAPER deterioration, *MECHANICAL behavior of materials, *PAPER deacidification, *WOOD-pulp products, *PRESERVATION of books, *HEAT, *HUMIDITY, *QUINONE
Abstract

Abstract: The damage to historical documents and books caused by the acidic character of paper is often manifested as a complete loss of their mechanical properties. Deacidification and restoration of archived paper objects require knowledge of the long-term behaviour of paper before and after repair actions. Our study was focused on the investigation of mechanical properties (tensile strength, stretch, tensile index, zero-span tensile strength, folding endurance) of original papers (one alkaline and three different acidic samples) exposed to five methods of dry-heat and moist-heat accelerated ageing. The degree of paper deterioration upon ageing was significantly influenced by the temperature and relative humidity, along with the intrinsic chemistry of the individual paper samples. The correlation matrix evaluated at a 95% confidence level for tensile strength, stretch, tensile index and zero-span showed linear correlations between these mechanical properties for all the paper samples. However, a linear dependence of folding endurance on zero-span tensile strength was found only for alkaline paper, which revealed the highest resistance to the accelerated ageing tests. In addition, the concentration of paramagnetic semiquinone species in the acidic lignin-containing paper samples was monitored by Electron paramagnetic resonance spectroscopy. [Copyright &y& Elsevier]

Published
2009
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2. Early detection of enzymatic attack on paper by NMR relaxometry, EPR spectroscopy and X-Ray powder spectra

Author

Corrado Fanelli, Maria Carmela, Donato Attanasio, Donatella Capitani, Giorgio Capretti, Bonaventura Focher, Annalaura Segre, and Anna Adele Fabbri

Subjects
Relaxometry, Materials science, paper, X-ray, Analytical chemistry, Early detection, Forestry, Spectral line, law.invention, epr spectroscopy, nmr relaxometry, enzymatic attack, Nuclear magnetic resonance, law, General Materials Science, Electron paramagnetic resonance
Abstract

Fungal growth on paper is one among the causes responsible for paper deterioration in archives and libraries. The study of paper deterioration is a complex phenomenon in particular when it is due to the biotic action of fungi and bacteria. One of the major problems is the early detection of fungal activity and, following an enzymatic attack, the evaluation of actual permanent damage on different types of paper. In this report we present a combined study based on NMR relaxometry, EPR (Electron Paramagnetic Resonance) spectroscopy, X-Ray powder spectra and chemical analysis. These methods altogether indicate that, in the case of an enzymatic attack by endo glucanase, it is the amorphous fraction of paper to be attacked. In particular, NMR relaxometry is able to reveal extremely mild enzymatic attacks, not observable with any other method.