Preparação e caracterização de complexos polieletrolíticos a partir de polímeros de fontes renováveis: uma abordagem sustentável

• Ano de defesa: 2023
• Autor(a) principal: Rodrigues, Marciele Gomes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; Brasil; Programa de Pós-graduação em Química
• Palavras-chave em Português: Quitosana; Chitosan; Lignosulfonato de sódio; Sodium lignosulfonate; Carboximetil lignina; Carboxymethyl lignin; Complexos de polieletrólitos; Polyelectrolyte complexes; Esferas; Spheres; Química; Chemistry; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA; Polímeros; Eletrólitos; Recursos naturais renováveis; Microscopia eletrônica - Técnica
• Link de acesso: https://repositorio.ufu.br/handle/123456789/39041; http://doi.org/10.14393/ufu.di.2023.470

The interest in the use of renewable polymers is growing due to their non-volatile and easily recyclable nature, making them ideal materials for applications in various fields. Therefore, the aim of this research was to obtain polyelectrolyte complexes and spheres through the association of oppositely charged polyelectrolytes, with the potential for industrial applications, using a simple mixing method. The polymers used included chitosan, cationic starch, carboxymethyl lignin, sodium lignosulfonate, and carboxymethyl cellulose. The formation of polyelectrolyte complexes (PECs) was achieved by contacting cationic and anionic solutions, resulting in successful interactions between chitosan and carboxymethyl lignin, as well as sodium lignosulfonate. Techniques such as Fourier-transform infrared spectroscopy (FTIR), thermogravimetry (TG and DTG), and differential scanning calorimetry (DSC) were employed to characterize the polymeric solutions and PECs, revealing molecular changes and differences in the thermal properties of the materials. Spheres with diameters of 3-5 mm were successfully produced through the interaction between chitosan and sodium lignosulfonate polymers. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirmed properties such as surface and internal porosity of the spheres, as well as the elemental mass content, respectively. In summary, the research demonstrated the feasibility of obtaining polyelectrolyte complexes and spheres using a cost-effective commercial approach.