Studies on the Weatherability of Paper Extract
| Autor: | Lin, Li-Ling, 林俐伶 |
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| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Paper extracts have some advantages that make them the retouching material. For example, the colors of paper extracts are close to old colors; besides, the light fastness of paper extracts are close to that of old colors, they may therefore have the same speed of color changing over time. However, whether the paper extracts include the degradation products, the lignin, for example, has long been doubted by the conservators. Moreover, the preparing process of the paper extracts, or the test results of weatherability of the paper extracts, often varied a lot in the previous studies. This previous studies-based experiment was conducted by adding two variables. The first variable was set up between the weatherability of paper extracts made of paper with lignin and paper without lignin. The second variable was set up between the weatherability of paper extracts that was being filtered and that was not. The four sets of different paper extracts were thus made to be absorbed in standard filter paper for the making of samples. These samples were then put into the artificial thermal aging experiment and the QUV aging experiment. Various paper properties were evaluated, such as discoloration, mechanical strengths, pH values, and degree of polymerization(DP). Besides, the main components of paper extracts were analyzed by the Gas Chromatograph Mass Spectrometer (GC-MS). If paper extracts is made of lignin, they will consist of more acid degradation products, and will be harder to be controlled by Ca(OH)2. These organic acid compound may further influence the performance of color weatherability, leading to a large decrease of DP of cellulose. Besides, the filtered set performed better on weatherability and pH readings on account of the removal of most of the solid degradation products, although the process of filtering cannot filter the main acid degradation products at all; while the unfiltered set performed better on viscosity, tensile strength, and folding endurance, because the cross-linking generated from degradation had the DP strengthened, and thus improved mechanical strengths. Furthermore, the paper sources of paper extracts also had great influence on the weatherability of paper extracts. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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