Selective Recovery of n-Butanol from Aqueous Solutions with Functionalized Poly(epoxide ionic liquid)-Based Polyurethane Membranes by Pervaporation

Abstract

In this study, hydroxyl-terminated polybutadiene–poly(epoxide ionic liquid)–poly(urethane urea) (HTPB-PEIL-PU) membranes, HTPB-PEIL1-PU and HTPB-PEIL2-PU, were prepared by the reaction of functionalized PEIL, poly(1-methylimidazole-3-methyl-ethyloxy)hexafluorophosphate or poly(1-methylimidazole-3-methyl-ethyloxy)bistrifluoromethanesulfonimidate, respectively, with HTPB using 4,4′-diphenylmethane diisocyanate (MDI) as the chain extender. The HTPB-PEIL-PU and HTPB membranes were investigated for the selective recovery of n -butanol from aqueous solutions by pervaporation. PEIL was confirmed to be successfully embedded in the PU membranes by 1 H NMR, Fourier transform infrared, and differential scanning calorimetry measurements. According to our mechanical measurements, the HTPB-PEIL-PU membranes retain the mechanical properties of the original PU membrane. PEIL was shown to enhance the diffusion rate of n -butanol significantly based on swelling behavior tests. The pervaporation flux through the HTPB-PEIL1-PU membrane increased with increasing feed temperature and feed concentration. In contrast, the separation factor of the HTPB-PEIL1-PU membrane increased with increasing feed temperature but decreased with increasing feed concentration. In addition, the HTPB-PEIL2-PU membrane exhibited an optimal separation factor of up to 29.2 at a feed concentration of 3% and a feed temperature of 70 °C, which is superior to that (22.7) through pure HTPB membranes. Furthermore, the HTPB-PEIL1-PU and HTPB-PEIL2-PU membranes show better long-term stability than other supported ionic liquid membranes.

Poly(ionic liquid)s: an emerging platform for green chemistry

“…Tang et al reported that hydroxyl-terminated polybutadiene-poly-(epoxide ionic liquid)-poly(urethane urea) (HTPB-PEIL-PU) membranes are capable of selectively recovering n-butanol from aqueous solutions. 168 PILs with ionic liquid species in their repeating units form a vast group of functional task-specific polymer materials. The application of PILs in SPME was first introduced by Anderson in 2008, by coating imidazolium-based PILs onto fibers.…”

“…Tang et al reported that hydroxyl-terminated polybutadiene–poly-(epoxide ionic liquid)–poly(urethane urea) (HTPB-PEIL-PU) membranes are capable of selectively recovering n -butanol from aqueous solutions. 168…”

1-Butanol Separation from Aqueous Acetone-Butanol-Ethanol (ABE) Solutions by Freeze Concentration

“…An overview of various separation methods applied in downstream processing in a biorefinery has been reported in the literature. , Separation methods have been studied specifically for biobutanol recovery from fermentation broths based on flash fermentation, distillation, , gas stripping, membrane separation, extraction, and adsorption . Previous research on various membrane-based separation methods for 1-butanol recovery such as pervaporation, , membrane separation with gas stripping, and perstraction has led to the development of better membrane performance with reduced toxicity and energy consumption.…”