resumo
This study introduces a highly efficient and greener alternative for recycling poly(ethylene terephthalate) (PET), a widely used polymer, and poly(ethylene 2,5-furandicarboxylate) (PEF), a bio-derived homologous of PET with market introduction announced to start in the very near future. The process involves the hydrolytic depolymerization of these polyesters into terephthalic acid (TPA) or 2,5-furandicarboxylic acid (FDCA), respectively, using natural terpenoid-based eutectic solvents (ES) under alkaline conditions. The synergistic effect of the ES components and sodium carbonate was found to be essential to prompt the depolymerization reaction. Characterization analyses by FTIR, NMR, TGA and elemental analysis confirmed the nature of the recovered products as well as of the high degree of purity. Additionally, the ES reuse was assessed, demonstrating its potential for 7 cycles without significant loss of catalytic activity, contributing to a reduction of process waste. Optimization of depolymerization conditions using a design of experiments (DoE) approach resulted in TPA and FDCA yields surpassing 90 and 80 %, respectively, using temperatures bellow 150 °C and not exceeding 5 h of reaction. Green metrics, which describe quantitatively the greeness of a chemical process, were determined. The obtained E-factors, ranging between 10 and 70, showed comparable results to the fine chemicals industry.
autores
Vinícius de Paula
nossos autores
Vinícius de Paula
Estudante de doutoramentoorientadores
Andreia F. Sousa and Armando J. D. Silvestre