Glicólise de PET pós-consumo catalisada por líquidos iônicos

• Ano de defesa: 2018
• Autor(a) principal: Silva, Carlos Vinícius Guimarães
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Química; Centro de Ciências Exatas; UFES; Programa de Pós-Graduação em Química
• Palavras-chave em Português: Glycolysis; Ionic liquid; Activation energy; Design of experiments; PET; Glicólise; Líquido iônico; Energia de ativação; Otimização multivariada; Planejamento de experimentos; Plásticos; Polímeros; Catalisadores de metal; Química; 54
• Link de acesso: http://repositorio.ufes.br/handle/10/7324

In the present work, the post-consumption polyethylene terephthalate (PET) depolymerization process was carried out using the glycolysis method with ethylene glycol catalyzed by dialkylimidazole ionic liquids synthesized from 1-butyl-3-methylimidazole chloride ([Bmin]Cl) in reaction with Zn2+and Mn2+chlorides.For each salt studied, the structure was confirmed by mass spectrometry by electrospray ionization in negative mode (ESI(-)-MS); the catalytic effect of the process was calculated by calculating apparent activation energies (Ea) determined by Arrhenius curves reaching 36.49 kJ/mol and 58.09 kJ/mol respectively; the behavior of the residual PET by electron microscopy (SEM) was evaluated and greater degradation was observed in the presence of [Bmin]ZnCl3, justifying the higher catalytic efficiency in the process also in comparison to the literature; Finally, the Box-Behnken optimization model was appliedthroughtheresponse surface methodology (RSM), in which three factors (time, temperature and mass ratio of ethylene glycol) were studied in three levels of variation (-1, 0, +1) with two replicates of the central point, totaling 15 experiments in which yields were estimated in bis(2-hydroxyethyl) terephthalate monomers (BHET), greater than 50% under the conditions established with the increase of the 3 variables together. The glycolysis products were characterized by mass spectrometry (ESI-MS), spectroscopic techniques (FTIR) and (¹H and ¹³C NMR), X-ray diffraction (XRD) and thermal analysis (TGA) and(DSC).