Gelation of Cellulose Derivatives: Searching for ionic liquid paper

• Autor(a) principal: Rosete, Inês M. Micael
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/25151
• topic: Cellulose; Cellulose derivatives; polymer ionic liquid; Gels; Nuclear Magnetic Resonance; Rheology; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química

Cellulose is the world’s most abundant, biocompatible, non-toxic, biodegradable polymer obtained from renewable sources. However its dissolution problems hampers a more generalized application. ILs are generally defined as organic/inorganic salts with a melting point lower than 100 C which present a good solubility for polar and non-polar compounds such as organic, inorganic or polymeric materials like cellulose. Cellulose solvents are scarce and, as such, the modification of its properties is a challenge. In this dissertation the main goal was to combine some of the unique IL’s properties with the intrinsic cellulose features. Thus, our strategy was to synthesize cellulose derivatives that enable the dissolution process in order to, later on, obtain a polymer gel. In the first stage we obtained ionic liquid grafted cellulose derivatives. Afterwards, we performed an extensive solubilization study to select the appropriate conditions to obtain the gel state. To further understand the solvents’ dynamics and their relevance in the gelation process, these conditions were followed by NMR and Rheology. The obtained results allowed the proposal of a gelation model for these cellulosic polymers. The proposed strategy could be a starting point to design and produce Ionic Liquid Paper (ILP), a material that could have potential for electrochemical applications.