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Type: Artigo de periódico
Title: Synthesis And Water Absorption Transport Mechanism Of A Ph-sensitive Polymer Network Structured On Vinyl-functionalized Pectin.
Author: Guilherme, Marcos R
Moia, Thais A
Reis, Adriano V
Paulino, Alexandre T
Rubira, Adley F
Mattoso, Luiz H C
Muniz, Edvani C
Tambourgi, Elias B
Abstract: Polysaccharide-structured copolymer hydrogel having excellent pH-sensitivity was developed from N,N-dimethylacrylamide (DMAc) and vinyl-functionalized Pectin (Pec). The Pec was vinyl-functionalized by way of chemical reaction with glycidyl metacrylate (GMA) in water under acidic and thermal stimuli. 13C NMR, 1H NMR, and FT-IR spectra revealed that the vinyl groups coming from the GMA were attached onto backbone of the polysaccharide. The hydrogels were obtained by polymerization of the Pec-vinyl with the DMAc. 13C-CP/MAS NMR and FTIR spectra confirmed that the gelling process occurred by way of the vinyl groups attached on Pec-vinyl backbone. The values of apparent swelling rate constant (k) decreased appreciably for pH greater than 6, demonstrating the swelling process of the hydrogel becomes slower at more alkaline conditions. There was an increase of diffusional exponent (n) with increasing pH of the surrounding liquid. This means the water absorption profile becomes more dependent on the polymer relaxation in basified swelling media. In this condition, a longer water absorption half-time (t1/2) was verified, suggesting the polymer relaxation mechanism of the hydrogel would have a considerable effect on the t1/2.
Subject: Acrylamides
Epoxy Compounds
Hydrogen-ion Concentration
Macromolecular Substances
Magnetic Resonance Spectroscopy
Molecular Structure
Phase Transition
Spectroscopy, Fourier Transform Infrared
Time Factors
Citation: Biomacromolecules. v. 10, n. 1, p. 190-6, 2009-Jan.
Rights: fechado
Identifier DOI: 10.1021/bm801250p
Date Issue: 2009
Appears in Collections:Unicamp - Artigos e Outros Documentos

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