Advanced search
Start date
Betweenand
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Characterization and physical-chemistry of methoxypoly (ethylene glycol)-g-chitosan

Full text
Author(s):
Facchinatto, William Marcondes [1] ; Fiamingo, Anderson [1] ; dos Santos, Danilo Martins [1] ; Campana-Filho, Sergio Paulo [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Sao Carlos Inst Chem, Ave Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: International Journal of Biological Macromolecules; v. 124, p. 828-837, MAR 1 2019.
Web of Science Citations: 4
Abstract

Methoxypoly(ethyleneglycol)-graft-chitosan (PEG-g-Ch) was prepared by grafting polyethyleneglycol into chitosans (Ch) exhibiting different average degree of deacetylation (60% < <(DD)over bar> < 95%). H-1 NMR showed that PEG-g-Ch derivatives presented high average degree of N-substitution (<(DS)over bar> approximate to 40%) and such derivatives exhibited full water solubility at 1.0 < pH < 11.0. The mPEG-g-Ch derivatives displayed much lower intrinsic viscosity (20 mL g(-1) < {[}eta] < 110 mL g(-1)) as compared to the parent chitosans (440 mL g(-1) < {[}eta] < 1650 mL g(-1)) due to extensive exposition of PEG chains to the aqueous medium and compact coiling of the chitosan backbone. The presence of numerous PEG chains grafted into chitosan also determined the crystalline arrangement and the thermal stability of PEG-g-Ch derivatives. The rheological study showed that the concentrated aqueous solutions of PEG-g-Ch derivatives displayed pseudoplastic behavior regardless of the parent chitosans characteristics and no dependence of dynamic viscosity on the temperature. However, PChD2 ((DD) over bar approximate to 76%; {[}eta] approximate to 1201 mL g(-1)) showed a distinct rheological behavior as it formed a physically cross-linked hydrogel that exhibited a thermo-induced sol-gel transition at approximate to 38 degrees C. (C) 2018 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 16/20970-2 - Study of chitosan and hydrophilic derivatives by time domain NMR
Grantee:William Marcondes Facchinatto
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 16/09720-4 - Use of membrane models to evaluate the biodegradability of chitosan
Grantee:Anderson Fiamingo
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 10/02526-1 - Studies on the effects of the high intensity ultrasound irradiation on the aqueous suspensions of chitin and chitosan
Grantee:Sérgio Paulo Campana Filho
Support type: Regular Research Grants
FAPESP's process: 17/20973-4 - Coaxial electrospun nanofibers based on chitosan for controlled release of antibiotics and periodontic lesion treatment
Grantee:Danilo Martins dos Santos
Support type: Scholarships in Brazil - Post-Doctorate