Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation
The thermal depolymerization of chitosan and alkaline deacetylation of chitin were characterized by measurement of viscosity, gel permeation chromatography (GPC), potentiometric titration (PT), and proton nuclear magnetic resonance spectroscopy (H1 NMR). The depolymerization rates (DR) measured by k...
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| Format: | Article |
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Wiley
2014-01-01
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| Series: | International Journal of Polymer Science |
| Online Access: | http://dx.doi.org/10.1155/2014/853572 |
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| author | Ana Maria de Oliveira Telma Teixeira Franco Enio Nazaré de Oliveira Junior |
| author_facet | Ana Maria de Oliveira Telma Teixeira Franco Enio Nazaré de Oliveira Junior |
| author_sort | Ana Maria de Oliveira |
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| description | The thermal depolymerization of chitosan and alkaline deacetylation of chitin were characterized by measurement of viscosity, gel permeation chromatography (GPC), potentiometric titration (PT), and proton nuclear magnetic resonance spectroscopy (H1 NMR). The depolymerization rates (DR) measured by kinematic viscosity (KV), apparent viscosity (AV), and GPC (Mw) until 4 h of treatment were DRKV=21.9, DRAV=25.5, and DRMw=23.3% h-1 and for 5 to 10 h of treatment they decreased slowly to produce of DRKV=0.545, DRAV=0.248, and DRMw=1.11% h-1. The mole fraction of N-acetylglucosamine residues FA of chitosans was not modified after 10 h of thermal treatment at 100°C. The initial FA values of chitosan without any treatment were FAPT=0.21 and FAHNMR1=0.22 and of chitosan treated for 10 h were FAPT=0.27 and FAHNMR1=0.22. The variables used to characterize the depolymerization process showed a good correlation. Six hours of thermal treatment as sufficient to obtain chitosans with a molar mass 90% smaller than that of the control chitosan without treatment. |
| format | Article |
| id | doaj-art-bca7a8f74c474c1bae80f2a773bc1720 |
| institution | Kabale University |
| issn | 1687-9422 1687-9430 |
| language | English |
| publishDate | 2014-01-01 |
| publisher | Wiley |
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| series | International Journal of Polymer Science |
| spelling | doaj-art-bca7a8f74c474c1bae80f2a773bc17202025-02-03T06:42:04ZengWileyInternational Journal of Polymer Science1687-94221687-94302014-01-01201410.1155/2014/853572853572Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline DeacetylationAna Maria de Oliveira0Telma Teixeira Franco1Enio Nazaré de Oliveira Junior2Department of Chemistry, Biotechnology and Bioprocess Engineering, Federal University of São João Del-Rei, Campus Alto Paraopeba, Ouro Branco 36420-000, MG, BrazilSchool of Chemical Engineering, State University of Campinas, Campinas 13083-970, SP, BrazilDepartment of Chemistry, Biotechnology and Bioprocess Engineering, Federal University of São João Del-Rei, Campus Alto Paraopeba, Ouro Branco 36420-000, MG, BrazilThe thermal depolymerization of chitosan and alkaline deacetylation of chitin were characterized by measurement of viscosity, gel permeation chromatography (GPC), potentiometric titration (PT), and proton nuclear magnetic resonance spectroscopy (H1 NMR). The depolymerization rates (DR) measured by kinematic viscosity (KV), apparent viscosity (AV), and GPC (Mw) until 4 h of treatment were DRKV=21.9, DRAV=25.5, and DRMw=23.3% h-1 and for 5 to 10 h of treatment they decreased slowly to produce of DRKV=0.545, DRAV=0.248, and DRMw=1.11% h-1. The mole fraction of N-acetylglucosamine residues FA of chitosans was not modified after 10 h of thermal treatment at 100°C. The initial FA values of chitosan without any treatment were FAPT=0.21 and FAHNMR1=0.22 and of chitosan treated for 10 h were FAPT=0.27 and FAHNMR1=0.22. The variables used to characterize the depolymerization process showed a good correlation. Six hours of thermal treatment as sufficient to obtain chitosans with a molar mass 90% smaller than that of the control chitosan without treatment.http://dx.doi.org/10.1155/2014/853572 |
| spellingShingle | Ana Maria de Oliveira Telma Teixeira Franco Enio Nazaré de Oliveira Junior Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation International Journal of Polymer Science |
| title | Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation |
| title_full | Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation |
| title_fullStr | Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation |
| title_full_unstemmed | Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation |
| title_short | Physicochemical Characterization of Thermally Treated Chitosans and Chitosans Obtained by Alkaline Deacetylation |
| title_sort | physicochemical characterization of thermally treated chitosans and chitosans obtained by alkaline deacetylation |
| url | http://dx.doi.org/10.1155/2014/853572 |
| work_keys_str_mv | AT anamariadeoliveira physicochemicalcharacterizationofthermallytreatedchitosansandchitosansobtainedbyalkalinedeacetylation AT telmateixeirafranco physicochemicalcharacterizationofthermallytreatedchitosansandchitosansobtainedbyalkalinedeacetylation AT enionazaredeoliveirajunior physicochemicalcharacterizationofthermallytreatedchitosansandchitosansobtainedbyalkalinedeacetylation |