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Gewählte Doctoral Thesis:

Doctoral Thesis - Abteilung für Chemie nachwachsender Rohstoffe, BOKU-Universität für Bodenkultur, pp 173. UB BOKU obvsg FullText

Data Source: ZID Abstracts
Mass deacidification treatment has been applied to books, in the libraries and archives, that were in jeopardy due to their acidity. Sustainability of mass deacidification was questioned due to lack of quality control systems and a risk of alkaline treatment to the original books, which have naturally aged for up to 150 years. In the present study, the aims were not only the assessment of the performance of mass deacidification processes, but also the study of the influence of mass deacidification on a molecular level of cellulose, focusing on β-elimination triggered by alkali. Over 400 books from the German Libraries were analyzed. Surface pH and alkaline reserve was determined for selected original books by different methods. Twenty-five deacidified books and their identical non-deacidified papers were analyzed by GPC coupled with fluorescence and light scattering detectors after fluorescence labeling of carbonyl groups, which offered deeper insights into degradation mechanisms. β-elimination triggered by keto/aldehyde groups along the cellulose chain seems to be unavoidable after mass deacidification as well as during accelerated aging. However, thanks to the characteristic distribution of carbonyl groups found in naturally aged book paper, β-elimination did not cause severe chain scission to an extent that lowered the molecular weight. The study of accelerated aging added to this finding. Degradation of original deacidified paper was overruled by the benefits from alkaline reserve, reducing acid hydrolysis remarkably, without being affected severely by β-elimination. Degradation of cellulose after accelerated aging did not correlate with the initial carbonyl group content prior to accelerated aging or to the lowered content of along-chain carbonyls after accelerated aging, which is a sign of β-elimination. Therefore, a threat of alkaline degradation under conditions of the mass deacidification tested was minor.

Betreuer: Potthast Antje
1. Berater: Banik Gerhard

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