Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin

Autores
Peralta, Micaela; Pajer, Nicolò; Crestini, Claudia; Nicolau, Verónica V.
Año de publicación
2024
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
In view of developing upcycling strategies for hardwood Kraft lignin, hydroxymethylation of Eucalyptus Kraft lignin under alkaline conditions (pH 9 and 11) at different temperatures (50 °C and 70 °C) was studied in the present effort with the double objective of optimizing the reaction conditions and understanding the functionalization mechanism of C5 in either terminal or internal guaiacyl units during hydroxy-methylation. Formaldehyde consumption was estimated via titration of the oximated free formaldehyde; the hydroxy-methylation degree under the reaction was estimated by calculating the ratio in Condensed hydroxyl/Guaiacyl (Condensed OH/G-OH) via a new difference UV-spectroscopy. The reliability of the difference UV-method results for the analyses of the hydroxy-methylated lignins was statistically analysed and compared with that of vacuum-dried and sonicated samples. Hydroxy-methylated samples were then fully characterised by NMR (31P and HSQC) and GPC. The reaction temperature of 50 °C, pH 11, and period time of one hour resulted as the optimal conditions for the hydroxy-methylation, preventing the side-reactions leading to the formation of dimethylene-glycol addition products.The 31P and 1H–13C HSQC NMR revealed the absence of undesirable formaldehyde Cannizzaro by-products and the lack of hydroxymethyl groups in the aliphatic side chain under the studied conditions. GPC analyses, comparing two methodologies, revealed increases in molar mass of the hydroxy-methylated samples upon the formaldehyde addition. The selective hydroxy-methylation at the C5 guaiacyl site demonstrates that Eucalyptus Kraft lignin is as a promising candidate for resolproduction
PID MAUTISF0007635TC
PID PATCBSF0008135TC
Fil: Peralta, Micaela. Universidad Tecnológica Nacional. Facultad Regional San Francisco. Departamento de Ingeniería Química. GPol - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.
Fil: Pajer, Nicolò. Universidad Ca' Foscari de Venecia. Departamento de Ciencias Moleculares y Nanosistemas - Centro de Ciencias de Coloides y Superficies; Italia.
Fil: Crestini, Claudia. Universidad Ca' Foscari de Venecia. Departamento de Ciencias Moleculares y Nanosistemas - Centro de Ciencias de Coloides y Superficies; Italia.
Fil: Nicolau, Verónica V. Universidad Tecnológica Nacional. Facultad Regional San Francisco. Departamento de Ingeniería Química. GPol - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.
Peer Reviewed
Fuente
Wood Science and Technology 2024
Materia
Lignin
Hydroxymethylation
Mechanism
Nivel de accesibilidad
acceso abierto
Condiciones de uso
2024-10-16T19:09:42Z
Repositorio
Repositorio Institucional Abierto (UTN)
Institución
Universidad Tecnológica Nacional
OAI Identificador
oai:ria.utn.edu.ar:20.500.12272/11636
Acceder
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oai_identifier_str oai:ria.utn.edu.ar:20.500.12272/11636
network_acronym_str RIAUTN
repository_id_str a
network_name_str Repositorio Institucional Abierto (UTN)
spelling Mechanistic insight into hydroxy‑methylation of hardwood kraft ligninPeralta, MicaelaPajer, NicolòCrestini, ClaudiaNicolau, Verónica V.LigninHydroxymethylationMechanismIn view of developing upcycling strategies for hardwood Kraft lignin, hydroxymethylation of Eucalyptus Kraft lignin under alkaline conditions (pH 9 and 11) at different temperatures (50 °C and 70 °C) was studied in the present effort with the double objective of optimizing the reaction conditions and understanding the functionalization mechanism of C5 in either terminal or internal guaiacyl units during hydroxy-methylation. Formaldehyde consumption was estimated via titration of the oximated free formaldehyde; the hydroxy-methylation degree under the reaction was estimated by calculating the ratio in Condensed hydroxyl/Guaiacyl (Condensed OH/G-OH) via a new difference UV-spectroscopy. The reliability of the difference UV-method results for the analyses of the hydroxy-methylated lignins was statistically analysed and compared with that of vacuum-dried and sonicated samples. Hydroxy-methylated samples were then fully characterised by NMR (31P and HSQC) and GPC. The reaction temperature of 50 °C, pH 11, and period time of one hour resulted as the optimal conditions for the hydroxy-methylation, preventing the side-reactions leading to the formation of dimethylene-glycol addition products.The 31P and 1H–13C HSQC NMR revealed the absence of undesirable formaldehyde Cannizzaro by-products and the lack of hydroxymethyl groups in the aliphatic side chain under the studied conditions. GPC analyses, comparing two methodologies, revealed increases in molar mass of the hydroxy-methylated samples upon the formaldehyde addition. The selective hydroxy-methylation at the C5 guaiacyl site demonstrates that Eucalyptus Kraft lignin is as a promising candidate for resolproductionPID MAUTISF0007635TCPID PATCBSF0008135TCFil: Peralta, Micaela. Universidad Tecnológica Nacional. Facultad Regional San Francisco. Departamento de Ingeniería Química. GPol - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Pajer, Nicolò. Universidad Ca' Foscari de Venecia. Departamento de Ciencias Moleculares y Nanosistemas - Centro de Ciencias de Coloides y Superficies; Italia.Fil: Crestini, Claudia. Universidad Ca' Foscari de Venecia. Departamento de Ciencias Moleculares y Nanosistemas - Centro de Ciencias de Coloides y Superficies; Italia.Fil: Nicolau, Verónica V. Universidad Tecnológica Nacional. Facultad Regional San Francisco. Departamento de Ingeniería Química. GPol - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Peer Reviewed2024-10-16T19:09:42Z2024-10-16T19:09:42Z2024-09-24info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articulopdfapplication/pdfWood Science and Technologyhttp://hdl.handle.net/20.500.12272/11636https://doi.org/10.1007/s00226-024-01596-5Wood Science and Technology 2024reponame:Repositorio Institucional Abierto (UTN)instname:Universidad Tecnológica NacionalengengPID MAUTISF0007635TCPID PATCBSF0008135TCInternacionalinfo:eu-repo/semantics/openAccess2024-10-16T19:09:42Zhttp://creativecommons.org/licenses/by-nc-nd/4.0/Attribution-NonCommercial-NoDerivatives 4.0 Internacional.2026-09-24T12:46:39Zoai:ria.utn.edu.ar:20.500.12272/11636instacron:UTNInstitucionalhttp://ria.utn.edu.ar/Universidad públicaNo correspondehttp://ria.utn.edu.ar/oaigestionria@rec.utn.edu.ar; fsuarez@rec.utn.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:a2026-09-24 12:46:40.48Repositorio Institucional Abierto (UTN) - Universidad Tecnológica Nacionalfalse
dc.title.none.fl_str_mv Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
title Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
spellingShingle Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
Peralta, Micaela
Lignin
Hydroxymethylation
Mechanism
title_short Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
title_full Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
title_fullStr Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
title_full_unstemmed Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
title_sort Mechanistic insight into hydroxy‑methylation of hardwood kraft lignin
dc.creator.none.fl_str_mv Peralta, Micaela
Pajer, Nicolò
Crestini, Claudia
Nicolau, Verónica V.
author Peralta, Micaela
author_facet Peralta, Micaela
Pajer, Nicolò
Crestini, Claudia
Nicolau, Verónica V.
author_role author
author2 Pajer, Nicolò
Crestini, Claudia
Nicolau, Verónica V.
author2_role author
author
author
dc.subject.none.fl_str_mv Lignin
Hydroxymethylation
Mechanism
topic Lignin
Hydroxymethylation
Mechanism
dc.description.none.fl_txt_mv In view of developing upcycling strategies for hardwood Kraft lignin, hydroxymethylation of Eucalyptus Kraft lignin under alkaline conditions (pH 9 and 11) at different temperatures (50 °C and 70 °C) was studied in the present effort with the double objective of optimizing the reaction conditions and understanding the functionalization mechanism of C5 in either terminal or internal guaiacyl units during hydroxy-methylation. Formaldehyde consumption was estimated via titration of the oximated free formaldehyde; the hydroxy-methylation degree under the reaction was estimated by calculating the ratio in Condensed hydroxyl/Guaiacyl (Condensed OH/G-OH) via a new difference UV-spectroscopy. The reliability of the difference UV-method results for the analyses of the hydroxy-methylated lignins was statistically analysed and compared with that of vacuum-dried and sonicated samples. Hydroxy-methylated samples were then fully characterised by NMR (31P and HSQC) and GPC. The reaction temperature of 50 °C, pH 11, and period time of one hour resulted as the optimal conditions for the hydroxy-methylation, preventing the side-reactions leading to the formation of dimethylene-glycol addition products.The 31P and 1H–13C HSQC NMR revealed the absence of undesirable formaldehyde Cannizzaro by-products and the lack of hydroxymethyl groups in the aliphatic side chain under the studied conditions. GPC analyses, comparing two methodologies, revealed increases in molar mass of the hydroxy-methylated samples upon the formaldehyde addition. The selective hydroxy-methylation at the C5 guaiacyl site demonstrates that Eucalyptus Kraft lignin is as a promising candidate for resolproduction
PID MAUTISF0007635TC
PID PATCBSF0008135TC
Fil: Peralta, Micaela. Universidad Tecnológica Nacional. Facultad Regional San Francisco. Departamento de Ingeniería Química. GPol - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.
Fil: Pajer, Nicolò. Universidad Ca' Foscari de Venecia. Departamento de Ciencias Moleculares y Nanosistemas - Centro de Ciencias de Coloides y Superficies; Italia.
Fil: Crestini, Claudia. Universidad Ca' Foscari de Venecia. Departamento de Ciencias Moleculares y Nanosistemas - Centro de Ciencias de Coloides y Superficies; Italia.
Fil: Nicolau, Verónica V. Universidad Tecnológica Nacional. Facultad Regional San Francisco. Departamento de Ingeniería Química. GPol - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.
Peer Reviewed
description In view of developing upcycling strategies for hardwood Kraft lignin, hydroxymethylation of Eucalyptus Kraft lignin under alkaline conditions (pH 9 and 11) at different temperatures (50 °C and 70 °C) was studied in the present effort with the double objective of optimizing the reaction conditions and understanding the functionalization mechanism of C5 in either terminal or internal guaiacyl units during hydroxy-methylation. Formaldehyde consumption was estimated via titration of the oximated free formaldehyde; the hydroxy-methylation degree under the reaction was estimated by calculating the ratio in Condensed hydroxyl/Guaiacyl (Condensed OH/G-OH) via a new difference UV-spectroscopy. The reliability of the difference UV-method results for the analyses of the hydroxy-methylated lignins was statistically analysed and compared with that of vacuum-dried and sonicated samples. Hydroxy-methylated samples were then fully characterised by NMR (31P and HSQC) and GPC. The reaction temperature of 50 °C, pH 11, and period time of one hour resulted as the optimal conditions for the hydroxy-methylation, preventing the side-reactions leading to the formation of dimethylene-glycol addition products.The 31P and 1H–13C HSQC NMR revealed the absence of undesirable formaldehyde Cannizzaro by-products and the lack of hydroxymethyl groups in the aliphatic side chain under the studied conditions. GPC analyses, comparing two methodologies, revealed increases in molar mass of the hydroxy-methylated samples upon the formaldehyde addition. The selective hydroxy-methylation at the C5 guaiacyl site demonstrates that Eucalyptus Kraft lignin is as a promising candidate for resolproduction
publishDate 2024
dc.date.none.fl_str_mv 2024-10-16T19:09:42Z
2024-10-16T19:09:42Z
2024-09-24
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv Wood Science and Technology
http://hdl.handle.net/20.500.12272/11636
https://doi.org/10.1007/s00226-024-01596-5
identifier_str_mv Wood Science and Technology
url http://hdl.handle.net/20.500.12272/11636
https://doi.org/10.1007/s00226-024-01596-5
dc.language.none.fl_str_mv eng
eng
language eng
dc.relation.none.fl_str_mv PID MAUTISF0007635TC
PID PATCBSF0008135TC
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
2024-10-16T19:09:42Z
http://creativecommons.org/licenses/by-nc-nd/4.0/
Attribution-NonCommercial-NoDerivatives 4.0 Internacional
.
eu_rights_str_mv openAccess
rights_invalid_str_mv 2024-10-16T19:09:42Z
http://creativecommons.org/licenses/by-nc-nd/4.0/
Attribution-NonCommercial-NoDerivatives 4.0 Internacional
.
dc.format.none.fl_str_mv pdf
application/pdf
dc.coverage.none.fl_str_mv Internacional
dc.source.none.fl_str_mv Wood Science and Technology 2024
reponame:Repositorio Institucional Abierto (UTN)
instname:Universidad Tecnológica Nacional
reponame_str Repositorio Institucional Abierto (UTN)
collection Repositorio Institucional Abierto (UTN)
instname_str Universidad Tecnológica Nacional
repository.name.fl_str_mv Repositorio Institucional Abierto (UTN) - Universidad Tecnológica Nacional
repository.mail.fl_str_mv gestionria@rec.utn.edu.ar; fsuarez@rec.utn.edu.ar
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