Analysis of lignin content in alkaline treated hemp fibers: thermogravimetric studies and determination of kinetics of different decomposition steps

Autor: Albert M. Manich, Gabriela Dayana Mijas Vélez, Inés María Algaba Joaquín, Manuel José Lis Arias, Marta Riba Moliner, Diana Cayuela Marín
Přispěvatelé: Universitat Politècnica de Catalunya. Doctorat en Enginyeria Tèxtil i Paperera, Universitat Politècnica de Catalunya. Departament d'Enginyeria Química, Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria de Materials, Universitat Politècnica de Catalunya. Departament d'Estadística i Investigació Operativa, Universitat Politècnica de Catalunya. POLQUITEX - Materials Polimérics i Química Téxtil, Universitat Politècnica de Catalunya. TECTEX - Grup de Recerca en Tecnologia Tèxtil, Ministerio de Ciencia e Innovación (España)
Rok vydání: 2021
Předmět:
Zdroj: UPCommons. Portal del coneixement obert de la UPC
Universitat Politècnica de Catalunya (UPC)
Digital.CSIC. Repositorio Institucional del CSIC
instname
ISSN: 1532-2319
0277-3813
Popis: Hemp (Cannabis sativa L.) is a plant of which, its ease of cultivation, structure and properties, provide it great potential for industrial applications; nevertheless, the unfavorable content of lignin complicates its processing, especially in the textile area. Thus, an appropriate knowledge of the delignification process would lead to treating hemp fibers as cotton fibers. In this work, hemp has been treated with an alkaline liquor [NaOH 1 M] at 110 °C during different times and afterwards, the substrates were chemically characterized in order to determine their lignin content and also analyzed by thermogravimetry (TGA). Through the correlation analysis, the relationship between lignin content, onset temperature of cellulose decomposition and loss of mass at the different decomposition steps were established. A hyperbolic kinetic model to explain the influence of alkaline treatment time on lignin content and also on the loss of mass at the four steps of decomposition of the samples by TGA up to 600 °C has been developed. Although it has been found that the degradation of lignin occurred across the entire temperature range, results have shown that the influence of treatment time has become clearly relevant on lignin content, Step2 (180.5 °C-273.5 °C) where a fraction of 10 to 16% of lignin was degraded, and Step3 273.5 °C-396.5 °C) where cellulose was mainly decomposed and 20% of lignin was also degraded.
Authors gratefully acknowledge the financial support for this research from the Ministry of Science and Innovation of Spain (Project MAT2016-79352-R) and from the National Secretary of Higher Education, Science, Technology and Innovation of Ecuador (SENESCYT) for Doctoral's Fellowship (No. CZ02-000926-2018).
Databáze: OpenAIRE