Biorefinery of paulownia by autohydrolysis and soda-anthraquinone delignification process : characterization and application of lignin

BACKGROUND Lignin is one of the most abundant polymers in nature. Its physical and chemical properties confer it a high potential for various uses including the production of thermoplastic matrices. This work characterized various types of lignin obtained by alkaline delignification of paulownia wit...

ver descrição completa

Detalhes bibliográficos
Autores: Zamudio Aguilar, Minerva Ana María, Alfaro Martínez, Ascensión, Alva Salazar, Hugo Eduardo de, García Domínguez, Juan Carlos, García Morales, Moisés, López Baldovín, Francisco
Tipo de documento: artigo
Data de publicação:2015
País:España
Recursos:Universidad de Huelva (UHU)
Repositório:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:inglês
OAI Identifier:oai:ariasmontano.uhu.es:10272/10272
Acesso em linha:http://hdl.handle.net/10272/10272
Access Level:Acceso aberto
Palavra-chave:Lignin
Composites
Polylactic acid
Autohydrolysis
Biomass
Descrição
Resumo:BACKGROUND Lignin is one of the most abundant polymers in nature. Its physical and chemical properties confer it a high potential for various uses including the production of thermoplastic matrices. This work characterized various types of lignin obtained by alkaline delignification of paulownia with soda–anthraquinone. The delignification process was carried out with or without previous autohydrolysis. The products obtained after evaporation or acidification were used to produce polylactic acid–lignin composites. RESULTS Subjecting the raw material to autohydrolysis prior to alkaline delignification provided a spent liquor (black liquor) containing an increased amount of extracted lignin (11.9% more than without autohydrolysis) and possessing a higher calorific value (14 822 kJ kg−1) than in the absence of an autohydrolysis stage. Thermogravimetric analysis revealed a strong impact of the autohydrolysis process, which provided residual delignification fractions containing abundant lignin and no degradation products of polysaccharides or other constituents of the raw material. Mechanical dynamics analysis of composites with lignin contents from 12.5 to 30% revealed an increased elastic (storage) modulus (E'). CONCLUSIONS Soda lignin has appropriate interaction with the polylactic acid, which allows it to be used for obtaining a composite with adequate physical strength characteristics.