Characterization of porous cellulose triacetate derived from kapok fibres (Ceiba pentandra) as a tool to enhance crude oil absorption

Oil spills are a common occurrence that threatens marine life, necessitating sustainable remediation methods. Polyvinylidene fluoride (PVDF) membranes are known for their hydrophobicity, chemical resistance, and thermal stability, but they are hindered by naturally low porosity due to the high-density polymer structure. To address this limitation, a porous polymer with synergistic properties was required. In this study, kapok (Ceiba pentandra) fibers, which possess high porosity, were acetylated to improve their chemical stability and then blended with PVDF. The development of this oil-absorbing PVDF/CTA membrane aligns with Sustainable Development Goal 14: Life Below Water. The kapok-derived CTA was characterized to confirm its high degree of substitution (2.9) and solubility in non-polar solvents. Converting kapok fiber into CTA improved its thermal stability, and the combination of crystalline and amorphous regions in CTA provided a balance between flexibility and structural integrity. The molecular conformation of CTA was verified by 1H-NMR and 13C-NMR. Incorporating CTA into the PVDF membrane significantly increased its porosity by 16%, enhancing oil absorption capacity. Only 1.828 m2 of the PC3 membrane, compared with 2.656 m2 of PC0, was required to absorb 1 kg of crude oil. The findings of this study strongly indicate that producing kapok-derived CTA can overcome the low porosity limitations of neat PVDF membranes. The membrane's surface area could be further maximized by incorporating it into a cassette-style flow cell membrane. High-porosity PVDF/CTA membranes thus have the potential to be an efficient solution for oil spill remediation in marine environments.