Surface Modification of Cellulose from Oat Hull with Citric Acid Using Ultrasonication and Reactive Extrusion Assisted Processes

This study aimed to produce modified cellulose extracted from oat hulls by an esterification reaction with citric acid (CA) employing ultrasonication and reactive extrusion assisted processes. Modified samples were characterized Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (DRX), scanning electron microscopy (SEM), wettability, oil water absorption capacities, adsorption capacity, thermal stability. From FTIR results it can be observed a new band for all at 1735 cm?1, confirming the esterification. The morphology crystallinity pattern of fibers not affected esterification, indexes ranged 43% (unmodified cellulose) 44–49% in samples. Both groups samples, obtained extrusion, showed decreases capacities (1.63–1.71 g/g) compared unmodified (9.38 g/g). It was increase retention capacity 1.80 g/g 4.57–7.31 after also presented higher affinity non-polar solvent wettability test. properties expand its use industry prove that used obtain esterified cellulose, being eco-friendly, simple, convenient processes short times.