Syntheses and characterization of new poly(ionic liquid)s designed for CO2 capture

Abstract

A series of new poly(ionic liquid)s-p(IL)s based on polyurethane structures were synthesized and characterized and their behavior evaluated in CO₂ sorption tests under different pressures. The synthesized materials were characterized according to structure, composition, and thermal stability, by techniques such as FTIR, ¹H-NMR, TGA and DSC. The CO₂ sorption measurements were carried out in a Magnetic Suspension Balance-PTGA and proved that the change of the components of the polymer chain directly indicates the sorption behavior. The best performance for CO₂ sorption (75.7 mol% at 20 bar) was achieved with the p(IL) PUA-02a obtained from HDI and PTMG-2000 with [bmim]⁺ as a counter-ion. The synthesized p(IL)s presenting nitrogenated and polyether structures into the backbone allied to imidazolium counter-cations proved to be worthy of note in the CO₂ sorption besides being based on poly(urethane) a versatile and low-cost material. The results also highlighted the good performance of PUA-02 when compared with traditional solvents used in pre-combustion process, as well as the p(IL)s described in the literature.