Obtenção de nanocelulose a partir da funcionalização da celulose por oxipropilação

• Autor(a) principal: Alves Lima, Mário Henrique
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFSCAR
• Texto Completo: https://repositorio.ufscar.br/handle/ufscar/12737
• topic: Nanocelulose funcionalizada; Oxipropilação; Celulose; Functionalized nanocellulose; Oxypropylation; Cellulose; CIENCIAS EXATAS E DA TERRA::QUIMICA; ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::MATERIAIS NAO METALICOS::POLIMEROS, APLICACOES; CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA::QUIMICA DOS PRODUTOS NATURAIS

The present study aimed to obtain functionalized nanocellulose through the oxypropylation reaction. Thereunto, the cellulose was submitted to an initial activation step with a sodium hydroxide solution, and then the reaction with propylene oxide in different values of molar ratio [OP]/[OHcellulose], in autoclave, maintaining the constant temperature at approximately 135ºC. After obtaining the functionalized cellulose, the functionalized nanocellulose is obtained after passing its suspension (2% in distilled water) through a microfibrillator mill. Functionalized nanocellulose, as well as the cellulose pulp used throughout the process, were characterized by Infrared Spectroscopy (FTIR), aiming to analyze whether the oxypropylation reaction was effective, evidenced by the appearance of new characteristic bands of the graft of the polyol chains . The samples were also characterized for their mass gain, Elemental Analysis (CHNS), Atomic Force Microscopy (AFM), X-Ray Diffraction (DRX) and Thermogravimetry (TG). The results obtained are indicative that there was a decrease in the intensity of hydrogen bonds, because in all the modification conditions used, the nanocellulose obtained presented dimensions similar to non-functionalized nanocellulose, requiring a smaller number of passes through the equipment.