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14. | | LOPES, R.; PACHECO, T. F.; MACHADO, F.; GONCALVES, S. B. Production of the recombinant expansin BsEXLX1 in K. pastoris using glucose as carbon source. In: SIMPÓSIO NACIONAL DE BIOPROCESSOS - SINAFERM, 21.; SIMPÓSIO DE HIDRÓLISE ENZIMÁTICA DE BIOMASSA - SHEB, 12., 2017, Aracaju, Sergipe. [Anais ...]. São Paulo: Associação Brasileira de Engenharia Química, 2017. Não paginado. Biblioteca(s): Embrapa Agroenergia. |
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Registro Completo
Biblioteca(s): |
Embrapa Agroenergia. |
Data corrente: |
15/03/2019 |
Data da última atualização: |
18/11/2019 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Circulação/Nível: |
A - 1 |
Autoria: |
VICTOR, P. A.; GONCALVES, S. B.; MACHADO, F. |
Afiliação: |
Priscilla Araújo Victor, UnB; SILVIA BELEM GONCALVES, CNPAE; Fabricio Machado, UnB. |
Título: |
Styrene/Lignin-Based polymeric composites obtained through a sequential Mass-Suspension polymerization process. |
Ano de publicação: |
2018 |
Fonte/Imprenta: |
Journal of Polymers and the Environment, v. 26, p. 1755-1774, 2018. |
Idioma: |
Português |
Conteúdo: |
A modified sequential mass-suspension polymerization was employed to ensure adequate dispersion of lignin into the monomeric phase. Due to its complex macromolecular structure and low compatibility with styrene, eucalyptus wood-extracted lignin, via a modified Kraft method, was esterified with methacrylic anhydride to ensure organic phase homogeneity into the reaction medium. Infrared spectroscopy showed a decrease in the hydroxyl band, a characteristic of natural lignin (3200?3400 cm−1) and an increase in the characteristic ester band (1720?1740 cm−1) whereas nuclear magnetic resonance measurements exhibited intense peaks in the range from 1.7 to 2.05 ppm (?CH3) and 5.4 to 6.2 ppm (=CH2), related to methacrylic anhydride. Comparatively, the esterified lignin also displayed an increase of its glass transition temperature for 98 °C, related to natural lignin, whose Tg was determined to be equal to 91 °C. Styrene/lignin-based polymers exhibited higher average molar masses in comparison to the values observed for polystyrene synthesized with similar amounts of benzoyl peroxide, due to the ability of lignin to act as a free-radical scavenger. Composites obtained with styrene and natural or esterified lignin were successfully synthesized, presenting regular morphology and proper lignin dispersion. Based on a very simple polymerization system, it is possible to enhance the final properties of polystyrene through the incorporation of lignin, which represents an important platform for developing attractive polymeric materials from renewable resources. MenosA modified sequential mass-suspension polymerization was employed to ensure adequate dispersion of lignin into the monomeric phase. Due to its complex macromolecular structure and low compatibility with styrene, eucalyptus wood-extracted lignin, via a modified Kraft method, was esterified with methacrylic anhydride to ensure organic phase homogeneity into the reaction medium. Infrared spectroscopy showed a decrease in the hydroxyl band, a characteristic of natural lignin (3200?3400 cm−1) and an increase in the characteristic ester band (1720?1740 cm−1) whereas nuclear magnetic resonance measurements exhibited intense peaks in the range from 1.7 to 2.05 ppm (?CH3) and 5.4 to 6.2 ppm (=CH2), related to methacrylic anhydride. Comparatively, the esterified lignin also displayed an increase of its glass transition temperature for 98 °C, related to natural lignin, whose Tg was determined to be equal to 91 °C. Styrene/lignin-based polymers exhibited higher average molar masses in comparison to the values observed for polystyrene synthesized with similar amounts of benzoyl peroxide, due to the ability of lignin to act as a free-radical scavenger. Composites obtained with styrene and natural or esterified lignin were successfully synthesized, presenting regular morphology and proper lignin dispersion. Based on a very simple polymerization system, it is possible to enhance the final properties of polystyrene through the incorporation of lignin, which represents an importan... Mostrar Tudo |
Palavras-Chave: |
Compósitos poliméricos; Polimerização sequencial; Polymer composites. |
Thesaurus NAL: |
Lignin; Styrene. |
Categoria do assunto: |
-- |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/194298/1/SILVIA-Victor2018-Article-StyreneLignin-BasedPolymericCo.pdf
|
Marc: |
LEADER 02235naa a2200205 a 4500 001 2107112 005 2019-11-18 008 2018 bl uuuu u00u1 u #d 100 1 $aVICTOR, P. A. 245 $aStyrene/Lignin-Based polymeric composites obtained through a sequential Mass-Suspension polymerization process.$h[electronic resource] 260 $c2018 520 $aA modified sequential mass-suspension polymerization was employed to ensure adequate dispersion of lignin into the monomeric phase. Due to its complex macromolecular structure and low compatibility with styrene, eucalyptus wood-extracted lignin, via a modified Kraft method, was esterified with methacrylic anhydride to ensure organic phase homogeneity into the reaction medium. Infrared spectroscopy showed a decrease in the hydroxyl band, a characteristic of natural lignin (3200?3400 cm−1) and an increase in the characteristic ester band (1720?1740 cm−1) whereas nuclear magnetic resonance measurements exhibited intense peaks in the range from 1.7 to 2.05 ppm (?CH3) and 5.4 to 6.2 ppm (=CH2), related to methacrylic anhydride. Comparatively, the esterified lignin also displayed an increase of its glass transition temperature for 98 °C, related to natural lignin, whose Tg was determined to be equal to 91 °C. Styrene/lignin-based polymers exhibited higher average molar masses in comparison to the values observed for polystyrene synthesized with similar amounts of benzoyl peroxide, due to the ability of lignin to act as a free-radical scavenger. Composites obtained with styrene and natural or esterified lignin were successfully synthesized, presenting regular morphology and proper lignin dispersion. Based on a very simple polymerization system, it is possible to enhance the final properties of polystyrene through the incorporation of lignin, which represents an important platform for developing attractive polymeric materials from renewable resources. 650 $aLignin 650 $aStyrene 653 $aCompósitos poliméricos 653 $aPolimerização sequencial 653 $aPolymer composites 700 1 $aGONCALVES, S. B. 700 1 $aMACHADO, F. 773 $tJournal of Polymers and the Environment$gv. 26, p. 1755-1774, 2018.
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