Physicochemical characterization of thermally treated chitosans and chitosans obtained by alkaline deacetylation
ARTIGO
Inglês
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 (H-1 NMR). Thedepolymerization rates (DR) measured by...
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 (H-1 NMR). Thedepolymerization rates (DR) measured by kinematic viscosity (KV), apparent viscosity (AV), andGPC (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 (F-A) of chitosans was not modified after 10 h of thermal treatment at 100 degrees C. The initial F-A values of chitosan without any treatment were F-APT = 0.21 and F-A1HNMR = 0.22 and of chitosan treated for 10 h were F-APT = 0.27 and F-A1HNMR = 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
COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
Aberto
DOI: https://doi.org/10.1155/2014/853572
Texto completo: https://www.hindawi.com/journals/ijps/2014/853572/
Physicochemical characterization of thermally treated chitosans and chitosans obtained by alkaline deacetylation
Physicochemical characterization of thermally treated chitosans and chitosans obtained by alkaline deacetylation
Fontes
International journal of polymer science Vol. 2014 (2014), n. art. 853572 |