Characterization of Porous Cellulose Triacetate Derived from Kapok Fibres (Ceiba pentandra) as a Tool to Enhance Crude Oil Absorption

Abstract

Abstract Kapok fibre is a natural fibre obtained from the seed pods of the kapok tree (Ceiba pentandra). Cellulose triacetate (CTA) is a cellulose derivative in which hydroxyl groups of cellulose were converted into acetyl groups. In this study, high purity cellulose was extracted from kapok fibres and was converted to CTA. The produced CTA showed a high degree of substitution (DS) (2.9) by titration, which was confirmed by 1H- and 13C-NMR. CTA was soluble in non-polar chloroform and the conversion of hydroxyl groups into acetyl groups was confirmed by Fourier Transform Infrared Spectroscoy (FTIR). From Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC) results, CTA is thermally more stable than delignified kapok fibre where at the same time, CTA needed more energy to crystallize. X-Ray Diffraction (XRD) showed the decrease in crystallinity of CTA compared to delignified kapok fibre due to the presence of acetyl groups. Visually, CTA produced is irregular in shape and porous. 1H-NMR and 13C-NMR were used to confirm the CTA produced by looking at the molecular conformation. CTA from kapok exhibited stability in higher temperature, is porous and less crystalline than unmodified cellulose. CTA significantly increased the porosity of PVDF membranes, thereby enhancing its oil absorption capacities and suggesting that CTA is suitable as an additive to improve the properties of a membrane that is specifically designed for oil spill remediation.