Isolation and characterization of novel agrowaste‐based cellulosic micro fillers from Borassus flabellifer flower for polymer composite reinforcement

Abstract Nowadays, interest in new natural cellulosic materials is increasing due to their higher properties and the motivation for researchers to advance high‐performance bio‐based composites. This study aimed at understanding the physicochemical and morphological properties, crystallinity, and thermal behavior of Borassus flabellifer flower micro‐sized cellulosic fillers. Cellulose has some unique properties, such as good mechanical properties, low density, biocompatibility, thermal stability, and biodegradability. The acid hydrolysis method was used to extract cellulose from the dried B. flabellifer flower. The crystallinity index value and crystalline size were calculated through X‐ray diffraction for the extracted microcrystalline cellulose and found to be 69.81% and 70.73 nm, respectively. The morphology of the extracted cellulosic filler was investigated by scanning electron microscopy and ImageJ software. The average size of the micro filler was found to be 26 μm. The Fourier transform infrared spectroscopy showed the extracted cellulose fillers being free from lignin, hemicelluloses, and other non‐cellulosic materials. Atomic force microscopy revealed that the surface roughness of the cellulose was less than 66 nm. The results showed that an agricultural residue can be converted into a valuable micro‐sized cellulosic filler material for polymeric composite applications that can withstand processing temperature up to 200°C. Here, the naturally occurring source of B. flabellifer flower could be used as a valuable substitute for more traditional sources like wood and cotton for the production of nanocellulose, nano‐additives, or nano‐reinforcing agents for water‐soluble biopolymers.