Synthesis and characterization of polypropylene glycol-based novel organogels as effective materials for the recovery of organic solvents

In this study, novel hydrophobic organogels were successfully prepared via the aza-Michael addition reaction method using diamino terminated polypropylene glycol and diphenylmethane bismaleimide as monomers, in the presence of a tri-amino functional polypropylene glycol as a crosslinking agent. The chemical structures, surface morphology, and thermal stability of the synthesized organogels were analyzed using Fourier transform infrared spectroscopy and solid-state CPMAS(13)C-NMR, scanning electron microscope, and thermal gravimetric analysis technique, respectively. The effects of various parameters, such as the monomer ratio, amount of crosslinker, and as well as swelling properties of organogels by solvent absorption tests were studied. According to obtained results, the solvent uptake capacity increased with decreasing crosslinker ratio up to 30 wt%. The maximum solvent absorbency of the synthesized organogels were determined as 730%, 504%, 271%, 224%, 95%, and 17% for dichloromethane, tetrahydrofuran, benzene, acetone, gasoline and diesel oil, under optimum conditions, respectively. In addition, reusability of the organogels was evaluated for 10 cycles, depicting no significant loss in absorbance capacity. The fabricated organogels showed high solvent absorption efficiency with prospects as suitable material for the recovery of a wide range of organic solvents.

Automated summary

Novel hydrophobic organogels were successfully prepared using the aza-Michael addition reaction method. The synthesized organogels showed high solvent absorption efficiency and reusability, making them a suitable material for the recovery of a wide range of organic solvents. Analysis of chemical structures, surface morphology, and thermal stability, as well as the effects of various parameters on the organogels, were conducted in the study.