Hydrolytic and Oxidative Degradation of Paper
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 0034-5806 |
| Online Access: | http://www.viks.sk/chk/res_2_01_67_83.doc |
| Abstract: | Summaries. Two samples of pure cellulose of different degree of polymerisation values were submitted to oxidation degradation by a specific agent (sodium metaperiodate) and by a non-specific agent (sodium hypochlorite). The degradation process was monitored by viscosity measurements in order to check the degree of polymerisation. It is demonstrated that both samples have similar behaviour and that the degradation process results in a common value. The samples were also submitted to FTIR spectroscopy and the results make obvious that different functional groups derive from the oxidation process. Conclusions. The results of this research support the hypothesis that there is a symbiotic action between acidity and oxidation on the depolymerisation of cellulose. The presence of functional groups formed by oxidation (carboxyl and carbonyl) increases the susceptibility of the p-glucosidic bond to hydrolysis reactions catalysed by a high concentration of hydrogen ions. The nature of the functional groups seems not to influence the phenomenon. The results obtained for the paper samples oxidized by sodium metaperiodate (NaIO4), that is for aldehyde cellulose, are comparable to those submitted to random oxidation (NaCIO). In order to evaluate and compare the effects of the specific and non-specific oxidation, the samples were submitted to FTIR analysis. The results of the spectro-photometric analysis demonstrated the importance of our sampling procedures for accurate identification of the functional groups introduced by the oxidative procedures in the cellulose molecule. The ability to absorb in the C=O region was influenced by the thermal treatment undertaken prior to analysis. Particularly informative for the identification of the functional groups is the presence or absence of compounds at around 1720-1740 cm-1 in the spectrum of the untreated sample. |
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| ISSN: | ISSN 0034-5806 |
