Betely Tekola (PhD)Intisar Kadir2024-07-312024-07-312024-06https://etd.aau.edu.et/handle/123456789/3343Polyurethane foam (PUFs) has emerged as a promising material for oil cleanup. However, its effectiveness is limited by its hydrophilic nature. In this study, petroleum-based polyol was replaced with different amounts of biopolyol (25−100 w/w) to prepare biopolyol-based PUFs with enhanced oil sorption capacity. The bioplyol was obtained by liquefying khat straw using glycerol as a solvent and sulfuric acid as a catalyst. The foams were produced using the "two shot" technique. The resulting foams were characterized using Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR), Scanning electron microscope (SEM), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Density and Mechanical strength test measurements. The FTIR and NMR spectra indicated that urethane linkages in biopolyol-based PUFs were formed, indicating that the chemical structure of the polymer was preserved despite the incorporation of bioplyol. SEM results showed that the cell shape is significantly affected by the biopolyol content, which resulted in inhomogeneous, irregular, and large cell shapes. TGA revealed that the onset temperature (Tonset) of the foams decreased with increasing liquefied bioplyol concentration, indicating alterations in thermal stability. The hydrophobicity of the foams increased with higher liquefied bioplyol content, as observed in the one-factor-at-a-time test. The density measurement reveals that as the liquefied bioplyol content increases, so does the density of PUFs, while the mechanical strength decreases. Notably, the modified foams exhibited improved oil sorption capacity in an oil and PUF/oil/water system. The optimum oil sorption capacity of 26.9 g/g was obtained at PUF-25, 20% of oil to water percentage and 60 minutes of contact time for laboratory-prepared waste water and 24.98 g/g for actual garage wastewater sorption tests. These results highlight the potential of Khat derived liquefied bioplyol-based PUFs as effective oil adsorbents for water cleanup applications.en-USBiopolyolKhatLiquefactionOil sorptionPolyurethane foamRSMThesis